93 Metro Idle Problem

I've noticed my metro when it's already warmed up and you come to a stop sign or light and shift into 1st gear the idle tends to die down ALOT. To the point I think it's going to stall but doesn't. Gets kinda shakey inside. Doesn't do it all the time. Any ideas on what to fix? And while I'm at it, where do I get new door hinges and or bushings? My drivers door is sagging quite a bit. No rust just bad bushings. Thanks