Hello, and welcome to Scarleteen!
First off, congratulations on realizing your asexuality! I'm sorry, though, that the discovery brings with it this distressing situation with your boyfriend and feeling like you have to have sex to make it seem like you love him. You don't owe your boyfriend sex when it doesn't feel good to you, no matter how patient he's been, and you are not stringing anyone along if sex isn't your cup of tea and it's difficult for you to have it. I doubt, also, that your boyfriend would be happy with sex that you have for his benefit, when it's not enjoyable for you in turn. Have you told your boyfriend that you're asexual and that physical intimacy doesn't feel good? How did he respond?
I think this article may be of help, a previous user had a similar issue:
I'm asexual, but my partner wants to have sex: should I just compromise and do it?
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