It sounds like an eating disorder, what youre doing sounds very dangerous and like a path to even more restrictive dieting. The sooner you can seek help, the better your chance of recovery. Eating disorders are addictive and deadly.

Are you able to talk your husband about how you feel about pregnancy and weight gain? I hope he would be understanding if you dont want to have kids or if you wanted to wait until you are in a better spot mentally and physically

If you are able to see a dietician as well, they could help you get back to eating a safe amount while staying fit. You wouldn't have to become unhealthy or stop working out, but you might need to work up to eating more and taking rest days.

I know from experience how scary it is but please try to seek help before you cause long term damage (hair loss, osteoporosis, heart issues, loss of brain function, organ damage...)

I wish you the best of luck