Also if the fluid level is correct, then it sounds like the transmission is fairly worn...try doing a fault code check Checking error codes VR/VS (Revised) and see if anything come up. A long shot if the fluid is brown or black, is to do a fluid and filter change and see if that makes any improvement. Last ditch method is to add a can of "transmission stop slip" - this will sometimes keep it going. A reco trans will set you back about $2000 fitted which ain't something to be sneezed at.
Good Luck and welcome to the forum.
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