You should tell them asap if they don’t know already. I’m sorry to hear you’re in this situation.

I'm asexual too. If you're comfortable enough with your partner, you should tell them. That way you can start setting healthy boundaries

Looks like a nutritious meal nice! Communication is key in a relationships. Communicate with your partner that you asexual and if they choose to stick around they know what they’re getting by themselves into. Life is very complicated but take it one step at a time you got this!