If a manual trans, could be the clutch is nearly worn out and slipping seriously. Soon it won't grip at all and you'll need a tow truck to get it to a shop. Try this; put the transmission in the highest gear and try to drive off. If that doesn't stall the engine right away, the clutch is on its last legs. If automatic, have an OBD2 code check done free at a car part store. Write the code down exactly, then study its definition:
https://www.obd-codes.com/trouble_codes/