Toprol-XL and frequent bouts

I have been on Toprol XL (25mg) for about a month and a half. It was perscribed because I was getting more frequent bouts of rapid heartbeat from mitral valve prolapse. After taking this drug, the immediate first effect was tiredness. Then after about a week I had more pain in the right calf area of my leg. I had some pain in the leg previous to this, so I didn't think much of it. But it got rapidly worse within a couple weeks. In addition, I started to develop severe pelvic/hip/buttock pain on the right side. I was having trouble getting up from a sitting position, getting in and out of cars, and trouble standing on my feet for more than 5-10 minutes. When I asked the cardiologist about it, saying that these symptoms seemed to coincide with the beginning of taking Toprol, he told me that it sounded like sciatica and had no correlation to the medicine. So I went to a different doctor who perscribed anti-inflamatories and physical therapy. But none of it helped, and, in fact, the symptoms got worse. After about a month and a half of all of this, essentially alot of pain and not being able to walk, I decided to wean myself off of this drug (a week of 1/2 dosages). The pain is virtually gone and I can now stand on my feet and walk again (all within the span of a couple days).