I'm On Venlafaxine 75 Mg Twice A Day. I've Tried

I'm on venlafaxine 75 mg twice a day. I've tried a lot of other anxiety depression meds before as well. This one now gives me chest discomfort and irregular heart beats. Not to mention horrible water retention. I've been to three other doctors and no one "feels comfortable" changing my medication but I feel like venlafaxine is hurting me.... It's gotten to the point where all I do is sleep and don't have any energy... What do I do?