Your clothes fit better because you are converting the fat you have stored to muscle!
Woohoo! A lb of fat is the same weight as a lb of muscle obvisouly but the muscle is smaller and more compact. Explaining the fit of your clothes. That's why you are able to do the video easier, you have built muscle! Also could be the reason you gained I would say, it weighs more per square inch.
I don't think your sugeron is going to care that much, so just keep doing your best not to gain too much and keep as healthy as we can before surgery. No worries my friend, we just keep plugging along and you are doing GREAT!
Angela