97 s10 need help!

i know my truck needs a clutch because of the grinding into 3rd and 4th gear but now theres a new problem. the truck now makes a horrible grinding noise when over 60mph and when shifting and when i take my foot off the gas the truck rocks side to side. WTF is it!? i was told it was the clutch and i would just need the clutch kit OR it was a motor mount. i dont have many tools so i cant do it myself but what do you guys think it could be?

Possibly universal joint(s). Raise both rear wheels off of the ground at the same time and use jack stands under the axle. Put the transmission in neutral with the engine off. Grab the driveshaft close to the yoke with both hands and try to move it up and down. Rotate it 90 degrees and try again. Do this on each end of the driveshaft, there should be no movement in the joints. If there is, the joint needs replacement. Post your results.

Are you hearing gear grinding or throw out bearing? Is there any clutch slippage? Actual Gear Grinding is usually internal in the tranny. Throw out Bearing You will hear when stepping on the clutch pedal and stops when you take your foot off of the clutch.