Hmm. Well, I consider myself pretty asexual so I guess I'll try to answer as best as I can.

First of, not wanting a relationship and not wanting sex are very different things. They are called Aromantic and Asexual respectively. Many asexuals actually really like cuddling and holding hands with people but the act of sex really does nothing for them. Now, asexuality has a wide range since it's difficult to fully define (as I'm sure you've read about to some extent) but if you aren't opposed to sexual relationships with some girl then I don't think you would fall under the category of asexual. For example, if there was someone (anyone you found attractive) that wanted to have sex with you, would you want to do it? That really sums it up fairly simply. Now, some asexuals do masturbate (there are very iffy definitions when it comes to asexuals haha) but the most important question is if you would do it with someone else.

The rest of what you have mentioned is just a distaste for how people view you in general. Most people will always yearn for some sort of companionship whether it be friends or lovers but what you describe fits more into a mixture of social beliefs and personality traits and much less to do with sexuality.