My advice would be to talk to your OB, maybe there is another options while breastfeeding. I think some of what you are experiencing is normal after birth stuff. Like the fatigue and low sex drive. I also would recommend waiting on Weight Watchers. The weight will come off, right now you need extra calories to feed your baby so as long as you are watching your portions and eating health combinations, don't stress. If you are hungry eat!
I just came off the mini pill myself and I didn't experience the extremes that you are but I felt pretty icky for the first few months. I chalked it up to normal after birth stuff. After all I was up all hours of the night lol. Once we got a sleep schedule under control it go a lot better. Of course they are constantly changing their sleep pattern so it gets better, then not so good, then great, then blah...lol
I would definitely ask your OB about the bleeding, call the office and talk to the nurse. I know my OB's nurse is great for that kind of stuff.
Good luck and hang in there, after all it's not going to be for too much longer and you will be back to normal!