I found myself in your position not too long ago. Are you shielding mainly against space animals? Probably. Okay, things to do in this situation. If you do end up shielding just do a n-air out of your shield and then wave land away and reposition yourself. But if you are playing correctly, this wont be necessary.
You should always focus on being aggressive against space animals, otherwise they will easily dominate you. Needles, down smashes, grabs, and tech chase/punishing should dominate your matches. If you do it correctly they should be off the stage with a needle in their face at 70% falling to their death as you quickly get onto the edge with some fast fallen reverse needles.
Just work on being aggressive is all that I'm trying to get across to you.