I had my thyroid out due to cancer on 1/22/08. then because of ha...

I had my thyroid out due to cancer on 1/22/08. then because of having to take a high amt of levoxyl (synthetic thyroid hormone) I was put on metoprolol for the palpitations. I recently had more surgery to take out cancerous lymph nodes in neck and my dose of metoprolol was increased from 25 to 50 mgs. I was only on 50 mgs for about 4 weeks when I developed depression, insomnia, swollen belly, acid reflux, swollen legs and anxiety. My mind started to go off on me and I had convinced myself that the cancer was in my brain and that's why I felt like I was dying. I was told by my doc that this med does not usually cause depression. I went over the facts and realized I felt pretty good until I started taking this drug. Even on the 25 mgs my legs which are really skinny, started to look like lumpy cottage cheese but I figured it was due to the thyroid removal. I didn't take it at all today because I just want to be rid of it. I know I need to wean off but how long do I have to?