naked

i I have 2014 mack pinnacle mp8 and mdrivre tranny that is giving me a lot trouble sometimes when is on low gear rpm jump and don't want change like jerking and when is on 12 speed sometime rpm lock and stay still on 12 rpm and truck don't accelerate and do anything for like 15 second onto I keep driving like normal I do it like 3 or 4 times a day now is like 10 or 15 time a day..I'm desperate I need help