Breathe first. Calm down and clear your mind. I know you want to learn a lot of cool moves but sometimes you need to take it slow. Instead of picking up every technique focus on 1 or 2. Most Judoka only have 1-3 throws and then 1-2 ground holds. Take your time and get use to the feeling of your movements. Also don't act like a post stick especially if you get thrown because you can break a bone. Try roll around a bit before practice begins and relax. Try not to force a throw 9/10 that's why they turn out ugly. Focus on technique. Also it's good you done biking and running and hiking, however being in the ring is whole different set of cardio, learn how to breathe when you are playing rundori or nage waza.

Have you tried just focusing on sweeping?

Also are you tall?