I'm where you're at right now in terms of exercise and staying in bed. Here's a tip that has helped in the past: do just 5min of exercise. Maybe you know of it, but there's this great channel on Youtube called "Fitness Blender" and they have anything from short + beginner workouts to HIIT. Another thing is stretching. When you stretch to improve your flexibility it gives you a goal to work towards. Hope this helps.