Not enough rebound

I'm leaning back too much on my kicks. I think it's amazing how little details in my fighting can minimize my effectiveness. Like- I'll all the sudden start doing something weird for some reason and wonder why I'm doing bad in fighting or something like that. I've been leaning back too much when I throw kicks keeping me from being able to rebound or throw more kicks easily. Other than that- I worry too much when I fight my instructors. I keep thinking too much about what they're going to do. I'm getting really frustrated when I fight people like Mr. Vernon and Mr. Lafon. Both use their hands more than I ever care to, and I'm just not doing well against them. Other than just much more hard work- I need a better solution. I won't let myself continue to be beaten. When I'm fighting I often keep myself from throwing something because I think they'll catch it- and then I second guess myself and slow myself down that way. I'm so frustrated.....