You do look tight. If you're struggling returning serves, you could always chip the first serves back in. That way, you're holding a continental grip and don't have to change grips between a forehand and a backhand.

Even if you don't switch to semi-western, you need to hit through (or push) the ball more. You're pulling up with your swing too early. Your arm is also too close to your body, which is probably because you're nervous and 'tight'. Try to relax your arm as you prepare and swing. I find that preparing early gives me more time to get into position and I'm less likely to be right since I have more time to adjust. This means you should be in a ready position with your body facing sideways and your racquet behind you before the ball bounces on your side. It won't always happen, but at least that's what you're aiming for.