You should be proud of yourself, thats an awesome effort!
I'm a personal trainer and I always tell my clients one. day. at. a. time.
Literally
focus on 1lb not 50. Once you lost 1lb, work on another lb. Its so much healthier and makes sure you celebrate the progress, because those stepping stones matter just as much as reaching the end goal.
I've got a really "fun" cardio pattern I can send you if you like. Its only 25 minutes and will boost your fitness quickly if you stick to it.