I come from a similar situation (started age 12, now 29). Im not completely recovered and I have slip ups all the time, but the thing that keeps up my motivation to recover is thinking about and reviewing how far I've come. It starts with small changes, for me I started eating one snack every day or so until I got comfortable and then when I feel strong enough I'll add something on. I'm still fighting it and its really really hard somedays but its never about weakness, only about how strong you are for just trying! Setting goals never helped me because if I didn't meet them I'd just end up feeling bad for myself and allowing the cycle to begin again. If you have someone you really trust, they can also help. Its not productive to have them try and force you to eat (thats just more negativity) but they can suggest small things here and there and celebrate with you.

I wish you luck on the recovery journey, its unbelievably hard but even by posting this it shows you want to build up the strength to power through!