Need help on defending against those Fast shots

I guess you are referring to singles and that you are serving short, as you usually would not have to worry about shots that go past you after serving short in doubles.

If you serve short in singles, you should be ready and even expect a fast return (fast lifts, drives...). If you have problems receiving those shots, try to anticipate them (if it's always one particular shot you cannot get) and be mentally ready for them; but don't move before the shuttle has been hit. If your opponent is being to aggressive on your short serves, flick him at times.

If you serve high in singles and cannot get fast shots (fast drops, punch clears), the reason could be that your serve is not deep enough or that you could improve your footwork.

 

There is a thread called «exceptionally good rushers» just a few weeks old, everything there can be applied here too, so we don[t have to write all things again and again.

 

The phrases in the original post that stood out were:
"I serve" and "I'm nervous".

A better serve gives the opponent less chance to hit at you aggressively.
Learning not to be nervous gives you better chance of responding appropriately.
Both of those improvements will come with practice and time. Not much in the way of short cuts.

 

Hitting the shuttle against a wall repeatedly improves reaction time and control. Also, its return (the shuttle off the wall) tumbling all the time and make very good practice for net rolls too. Initially, there will be many misses and very short hits but as you practice more it'll get longer. Than you can draw a line on the wall to simulate net height and practice returning over the line. In no time after this your confidence will build up at net play and it becomes second nature. In fact you'll be eager to exchange fast pushes after this with anyone, myself included, if we get to play. Hope it helps.