Experiencing Anovulation Due to Eating Disorder: Need Advice

ive been underweight for a while as a side effect from a med, at my lowest my period just stopped coming, but it came back but is still pretty irregular. Im on birth control to help with cramps, and even with that its not super regular, if im late one day ill have breakthrough bleeds. Ive been trying to gain weight and whenever ive gotten consistent with feeding myself my periods got more regular too. Try making sure youre eating at least one or two good meals a day consistently and see if that helps. also keep snacks around. Im trying peanutbutter and milk for healthy calories.