Infertile/Cancer (long but please read, I need help/advice)

Codi
My first husband and I conceived when I was 17, the pregnancy ended in miscarriage around 12 weeks. We got pregnant again 7 months later and that pregnancy ended in miscarriage around 8 weeks. This ultimately led to divorce because he wanted kids and I couldn't give them to him. I met another man, thought I was in love, and we got married. We tried for 3 years and became pregnant 3 months before our wedding, I miscarried the day before my bridal shower. I made an appointment to see an infertility specialist and we were both ready to find out what the problem was and how to "fix" it. About a month before the appointment he told me wasnt going because there is nothing wrong with him so I could go by myself and figure out what's wrong with me. This led to divorce number 2. I rekindled things with an ex of mine and he has been going with me to my appointments. He has been extremely supportive and sweet about the entire thing. As of a week ago, they had run every test possible and couldn't find an issue with me. I went in for another ultrasound on Tuesday and the doctor walks in the room and says "I'm gonna cut the crap. I think you have uterine cancer." He does my ultrasound and points out some problems with my uterus and then tells me to schedule my tests before I leave. I have been scared beyond belief for days. To make matters worse the gal that schedules the procedures wasn't there when I was leaving my appointment so they told me to call the next day. I did and she told me I had to come in while I was on my period so I need to have it done on the 20th. I told her I wouldn't be on my period on the 20th and she tells me I need to be or they'll see me next month?! So I have to wait a month because I can't make my period happen on a certain day! Has this happened to anyone else? I feel lost and alone and scared and I don't know what to do:-(