13lbs in two months...
ehhh. That's definitely tough, especially at the weight you're at now. I don't think you should feel discouraged or "fat" at all. You've lost almost 40lbs. I'm sure you look amazing. I know how hard it is to see the results on ourselves, but everyone else must certainly be able to see them on you!
Why do you think you keeping messing up? I think you should focus on that instead of driving yourself insane trying to meet a goal that (while possible) would certainly be difficult. Why not reevaluate whatever plan you're following and see how you can make your 50lbs goal that way. Maybe not by a specific date...but just overall. I would also try and set non-scale related goals. I really want to run a 10k race in under an hour. I want to be able to do a chin-up. Sometimes the scale can be a pain in the *** and while yes, we want to lose weight, it's important not to get
too consumed by it.
I'm going to get off my soapbox now, because God knows I'm the most obsessive scale person ever.