Actually, there's a lot of things going wrong, and it'll take some time to elaborate though them.
For this post, the biggest error on your forehand is your racket takeback. RIGHT BEFORE the swing, your racket is ABOVE head level. This is entirely inappropriate. (I don't know how to screen capture, but at 3:11 is when it's most clear.) Swing low to high, as you're accelerating through the ball. You're accelerating high to low, then ending up high. That's different. You see what I mean?
When their tennis really matters, Babolat Reps use a Wilson.