Stalling issues

I have a stalling problem. Every time I'm coming to a stop or slowing down to turn my Idel goes so low that I end up stalling out .I pop the clutch and stick it into first or second depending the speed and it starts right back up. it's a 91 ' sport manuel tranny . my speedometer sensor just went out also. so does anyone have any idea as to what sensor I need to replace or is it the speed sensor that is causing this to happen. Thanks Matt

91 could be different, but in '01 the speed sensor (VSS) alerts the PCM (ECU) when the speed goes down and you're going to idle so that the Idle Actuator can position itself in time.
Fix that VSS first.
If nothing improves, then clean your Throttle body and check/change the Idle Actuator.
After that, check/change the TPS (Throttle position sensor).

When the VSS went south on my '92 XJ two years ago I didn't have any issues at all.
Take the IAC module out of the TB and clean that and the retaining barrel thoroughly because it may be sticking.