Is my clutch bad?

Hey new to posting but have used this site for many fixes and research. Im sure there are many threads on this but couldn't find anything. Im currently debating on if my clutch needs to be replaced. For the last two years the RPM's would increase while getting on the highway and there is little power increase. This problem started around 35,000 miles and the shop said there was nothing wrong with it. Originally it would only happen on cold days but has recently started to act up on moderately nice days. A guy I work with told me to clean out the throttle body and mass air sensor which i did. Ran like a new car for a couple of days and then it happened again. I don't smell the clutch burning. Truck currently has 82,000 miles on it. Not sure if the K&N intake would affect it. Any thoughts?

 

If you are on the gas and the clutch slips , there is an issue with the pressure plate clamping force .
You need a clutch .
https://www.marlincrawler.com/transmission/shifter-parts/heavy-duty-sockets

https://www.tacomaworld.com/threads...on-your-5-speed-transmission-write-up.338836/

 

Thank you. I was fearing that. Was hoping it wasn't as it stalls in first and the clutch pedal doesn't feel like its slipping. Felt like the throttle was stuck open. Will be going back to the shop in a few weeks.