N62 6spd transmission problems.Software reset/ update time?

[four.8is]

Guys my tranny has been acting up lately especially uphills..its horrible..shifting all over the place or not shifting at all til it reaches over 1000rpm's..
On the highway is smooth..but slower speeds, under 20mph especially its not good.Slows me down like its braking by itself.Downhill same thing..it downshifts by itself .It never knows when and how to shift except the time im on the freeway at higher speeds..then it gets it's "brains" back .

What are my options right now?reset?new tranny software?New transmission oil change and filter?I'll try anything except changing the tranny.