97 Jetta vr6 starts hard sometimes/sporadic idle

I have 97 Jetta vr6 that has me stumped. Sometimes starts hard and idles up and down as if I'm bumping the throttle but smooths out after a few seconds. Drives down the road really well but when you pull up to a stop light/sign it idles way down and dies sometimes and other times it does its goofy idling up and down thing. If it stays running it smooths out again after a few seconds. Has been getting worse lately. Dies almost every time you stop. I've heard change the coil. Change the mass air sensor. Change the throttle position sensor.I can't afford to just start changing things until it clears up. Also the speedometer and tachometer don't work, but the other gauges do. Sometimes all gauges don't work. Give it a good smack on the dash and u can usually get the temperature gauge and fuel gauge to come back on and the speedometer needle just barely twitches. I love the car and would like to get it straightened out ASAP. Any help or guidance to fix these problems would b greatly appreciated. Thank you for your time.