Asexual partner?

My boyfriend and I have been living together for about 9 months and he doesn't seem to want to be intimate with me. He works from home and I can't get any alone time when I want to relieve myself. When I tell him I'm in the mood nothing happens.

I've been very patient with him. And let him know he doesn't have to do anything if he doesn't want to.

But I definitely need alone time. I need time to help myself. I feel like masterbation is very normal and healthy. Yet I can't seem to do it because he's either right next to me or he keeps walking in on me and I lose the mood.

We have talked about it before and I usually get the reasoning that he's stressed or that he doesn't feel worthy of me. Which I always remind him how much I love him and want him.

I don't know what else to do.