How can i control my jealousy around my pregnant friend?

ok so long story short i have pcos, have been trying to conceive for 2 years after having 2 miscarriages, and am currently on fertility treatments that as of right now are not working. ive been going through all sorts of emotions but the biggest one other than sadness is jealousy. last year one of my best friends in the whole world (i have 3 im super close with) got pregnant by accident and didnt want the baby. i was angry and jealous. well..ive always pictured myself having a little girl, so when i find out someones having a girl, i get more jealous (dumb, i know). well she found out she was having a girl, and was MAD. she decided she wanted a boy. she had her november 18th. now this year, my other best friend is having a baby and is due november 17th, and found out today its a girl. so exactly a year apart, my two best friends. now i also find out my 3rd best friend is very late on her period which never happens and she's been trying and didnt tell me. all of this is just causing me so much anguish. and jealousy. i dont treat them badly, i hide it, and work very hard to do it. and they always say they appreciate how supportive i am. but its getting harder to do, and i feel like im dying inside. how can i control my jealousy and get over my sadness?