I Am 41 Years Old And A Female That Has

I am 41 years old and a female that has 4 children. My last child was born when I was 36 & he was 9 weeks premature. My periods have been irregular since then. The last year it has gotten worse. Very recently I have lost 25 pounds off my already small frame. I'm 5'6 & weigh 122 pounds. I just had my period for 9 days. it stopped for 4 days and seems to have started up again tonight. I'm tired all of the time. I'm also going through a divorce and a ft college student so have been equating all of this to stress.