'98 Camry

Last summer it was fine, then I noticed over the winter that when I put front window defog the compressor did not seem to be kicking in so I thought what the hell.

Now the outside temp isn't as cold anymore in March, and when I start a/c or put windshield defog the compressor usually kicks in wich results in idle rpm going slightly up, then it slides back down and the compressor dies. Then it wont kick in if I put a/c immediately back on. 20 Minutes later it will do the same thing : strat/stop.

Is it starting to be empty so it stops instead of eating itself or it stops because it's already a bit cold outside?

Please help me I want to fix this (if there's any problem) before summer.

I am sorry I do not know much about ACs, but my guess would be low on refrigerant.

Sam