1993 GMC C2500 Transmission repair guideline

The auto trans didn't want to shift, so I replaced the 1-2 shift solenoid and now some times it shifts hard
into second, it done this before the solenoid went out and stopped shifting 1-2 besides when it was cold and first started driving it.

Now it's shifting 1-2 but it does shift hard often as if it had a shift kit in it but it doesn't. What else can I do? It has new oil and filter. Does one of these solenoid cause the problem;
pressure control solenoid, Tcc solenoid pulse width modulated, regulator solenoid, lock-up solenoid,

Second problem my truck brake lights won't light up?
I have changed the pedal switch twices, bulbs, fuse,
what else could it be? Is there a relay that could cause the problem or factory in line fuses before the rear tail lights that could effect it in the wiring itself?

I need this truck operational to get me back and forth to work badley, thanks, Jim