Metoprolol Tartrate and loose weight

I am taking 25mg tablets for Afib in conjunction with warfarin. I still have Afib and I cannot loose weight. I have been on a high fiber, fruit, salad, small portion diet for one month. I weighed 285 when I started and weigh 285 now. Before taking Metopolol I was hypotensive. My normal BP was 90 over 50. My pulse was in the low 50's. Now my BP ranges from 165 over 95 down to 90 over 50. My pulse has hit as high as 200 but fluxes between 100 and 50. I have also developed diabetes type 2 and high colesterol. I am not sure if these are related to the Metoprolol or not. I also suffer from bipolar and PTSD. I am 60 years old.