I’m not impressed with your boyfriend, OP. I don’t know how somebody can be sexual with somebody that they know doesn’t want to be sexual. As if that isn’t problematic enough, he’s displacing his fears and insecurity onto you, despite you reassuring him that your lack of libido is nothing to do with loss of attraction. He’s making you responsible for his feelings, plus he’s perfectly happy to have sex with a woman who doesn’t want to. That is very problematic. I don’t even know how he can get turned on knowing that you have no interest and don’t want it. How could somebody get turned on in such a scenario? You would think it would feel wrong to him, and he wouldn’t want you to do it. If you don’t want to be sexual, OP, don’t feel obligated to. You’re not obligated to do anything for a partner. You’re not obligated to be sexual.
Regarding your loss of libido, can you reflect on when you did have a sex drive and compare your circumstances then and now. Besides stress, is there any other conditions that are different? Has any major life event occurred? Have you had any health issues?
Do you consider yourself allosexual? Is it possible that you could be graysexual and only feel sexual under certain, specific circumstances? If it’s possible, then perhaps those circumstances are not present at the moment.
There could be many factors that are causing this, or you could just possibly be going through a phase, and it will return in due course.