I have been having the following symptoms for awhile now (I do have a DR appt on Monday)....?

In December I had an irregular Pap, so I had another one to test for cancer cells, and she said everything looked ok, but to come back again in 6 months. Since then, I switched to the Patch (from BC Pills) and started Zoloft. I started to bleed in between periods. My Gyno said that was normal when taking new medications. She said it would happen for the first few months. Well, it is July and it is still happening. Normally, it was just a little bleeding but for the past two months my periods have been wack! Last month it was very late, then it was lighter than normal. On Wednesday I developed the worst lower back pain of my LIFE. It has centralized to the lower left side/hip and occasionally pain down my left thigh. The right side hurts a tad, but nothing like the left side. I literally cannot stand for more than 10 minutes doing an activity before I have to rest. But, laying/sitting doesn't help. Pain relievers have no effect whatsoever. About the time the back pain started, the headaches got intense. And finally, the past four days I have been bleeding again. But, the blood is brown/black and has occasional clots that are either stringy or mushy (gross, sorry). I have been having many bowel movements, that are sometimes a little pushed and hurt (my back). Uterin and Bladder cancer run in my family....however, I have had no urination problems at all. The fatigue I have is incredible, even with 8 hours a sleep a night, I still nap for at least 3 hours a day. I have a Dr appt on Monday, but any ideas as to what I may expect? Like I said, it's just this intense back pain that seems to get worse everyday.....like, not even a hair better each day.....Thanks!!!!