When I first happened across your incel site, I thought that it couldn't possibly have anything to do with me.  After all, at age 21, I'm a virgin because I want to be.  I'm waiting for the right person, and I'm fine with that.  The thought of a meaningless sexual experience, outside of a loving relationship, repulses and almost frightens me, and I guess I've implicitly assumed that when "The One" comes along, I would know because I would feel completely comfortable opening myself up - metaphorically and literally. 

Then, after I read a little more of what you had to say, it occurred to me that my ongoing search for the right person has quite a bit to do with incel.  Let me babble some more and see what you think...

I've always been pretty shy about all kinds of interpersonal relationships.  I've never been talkative, using the excuse that I only talk when I have something to say.  ("That must not be very often, then," said my teammate on the math team in seventh grade, which got him a dirty look from the teacher.)  In high school, I was pretty much of a social outcast, but I've gotten better since I've been in college.  I consider myself to be a nice person, I get along with most people I know, and I have a few close friends.  But frankly, I'm scared about what will happen when I graduate next month - whether the friendships I have are strong enough that we'll still keep in touch, and whether I'll be able to make friends when I get to graduate school in the fall.  Every time I've been introduced to a new social situation, I've been scared out of my mind that nobody will like me - even though everything's always turned out fine so far.

I still have no idea whether I'm homo-, hetero-, bi-, or a-, probably because my sexual side has been very late in developing.  I started flirting with cute boys in sixth grade, because everyone else was.  I've even had two relatively long-term boyfriends - more about them later.  But I don't remember feeling anything sexual at all until I was about 20.  When I was 18-19, I spent a lot of time reading erotic stories on the net, but mostly out of curiosity - I don't remember ever feeling aroused at all, and I certainly had no desire to engage in any of the activities described in the stories. 

Right before I turned 20, I came to the conclusion that I was asexual, and that I should learn how to be a happy asexual as well as I could.  I would watch talk shows where women complained about their cheating husbands, and I would consciously tell myself, "See that?  That's something that you'll never have to worry about."  But ultimately, I found the prospect of going through life without a partner so depressing that I decided to put it out of my mind.

Strangely, it was only a few months later that I realized that I had a sexual side to me after all.  I found myself daydreaming about sex and intimacy more often, although more often than never is still not very often.  I started developing some elaborate sexual fantasies, but none of them involve particular people, so I can't really say that I'm physically attracted to anybody at all.  In fact, I usually can't even decide whether the person on the "other end" should be male or female.

At the time, I didn't really associate the development of my sexuality with my resolution to stay out of romantic relationships.  I spent my junior year of college working on being happy being single, and focusing on developing other aspects of my life.  And it worked - I was very happy that year.  I remember thinking once in a while, "My life is really good right now, but it would be even better if I had a significant other to share it with," but I learned how to put those thoughts out of my head pretty easily. 

Then I met Dave, my second boyfriend, but I suppose that I should first talk about Alex, my first:

I met Alex at a summer program when I was 16.  We became fast friends, kept in touch after the program, and mutually concluded that we really liked each other, enough to put the effort into maintaining the long distance relationship.  He was more outgoing than I was, and had a stronger personality, so he ended up being in control most of the time.  He was also much more enthusiastic about physical intimacy than I was.  I remember spending hours on end lying on his bed or in his car, with him lying on top of me and trying over and over to lift my shirt, while I struggled to push it back down.  This was only one manifestation of his complete lack of respect for my feelings.  A year into the relationship, I decided that I'd had enough, and tried to break things off.  He told me in no uncertain terms that I had no right to be angry with him, because all the problems in the relationship were actually my fault, but since he was such a nice guy, he would forgive me and continue the relationship. 
This continued for another year.  Finally, the next summer, he told me matter-of-factly that he'd been involved with another girl.  He didn't understand why I was upset about this.  I never spoke to him again.  Needless to say, the whole ordeal ripped my self-esteem to shreds.

I met Dave last summer, under similar circumstances - we were together for a short time, kept in touch, and decided we wanted to start a relationship.  I told him about my uncertainty about my sexuality, and he said that even though he was very attracted to me, he could do without physical intimacy in the relationship if I wasn't comfortable with it, and that he would never pressure me to do anything I didn't want to.  He rebuilt a lot of the self-esteem that Alex destroyed - he made me feel attractive and desirable, and it felt good.  He always listened to me when I had something to say, and always respected my feelings.  But I never felt attracted to him in return, and I certainly wasn't in love with him.  We tried all sorts of things: romantic dinners, nights out dancing, long walks together.  But it always felt to me like something was wrong with the picture, and it felt more and more uncomfortable.  About two months ago, I told him about this, and that I didn't want to continue the relationship anymore.  He was hurt, but respected my feelings.  I'm still trying to keep him as a friend, but I don't know if it will work out.

It's hard to tell if I'm an incel or not.  I'm not looking for a sexual relationship - not right now, and maybe not ever.  I used to think I wanted an emotional, romantic relationship, but now I'm not so sure.  Romance is nice to idealize about, especially because of the pressures from society to form couples, but for me it never seems to be as good in practice as it is in theory.  I still dream about meeting Prince (or Princess) Charming, riding off to our castle on a white horse, and living happily ever after, but I've never met a real person who I thought could even come close to fulfilling that ideal.  I do feel very lonely sometimes, but I don't know if a significant other would remedy that. 
With any luck, it will all become clear, eventually.