What Causes Sudden Loss In Weight With Red Bumps On The Lower Legs?

Since September I have lost a total of 30 pounds. I lost 20 in the month of September and the rest have just been falling off these past months. I have been having a fast heart rate of high 90 s to low 100 s. I also have bruise like marks and small red bumps on my legs but mostly on my lower legs. I got a colonoscopy done and my colon is fine. I have gotten blood work done and they checked my thyroid and that was fine. Everything else was good except it showed that I had inflammation somewhere. That is why I had the colonoscopy done. I had an echocardiogram done of my heart too and that was fine. No one seems to know what s wrong with me. I have an appointment to see a hematologist but I was hoping maybe someone on here could help me.