HELP! Compressor now trips breaker on start up??

OK all of you electricians out there....LOL

I have a 15 year old 120 v 5 hp Craftsman compressor with a 33 gallon tank. I added a switch to the circuit so I can shut the compressor off when I am locking up the shop. It's on it's own 20 amp circuit. Now, the breaker trips sometimes when I turn the new switch on or the compressor tries to start, but doesn't, then trips the breaker, or I turn the switch off.

Any ideas? I thought it would work well with the switch, but it is obvious that the compressor does not like it. Any help on this would be great. Thanks