Transmission problem

[Akaiso]

Av changed gear oil but problem persists but dash light shows orange not red. In d morning at first drives accelerate well but when d engine hots up acceleration declines as if car that d clutch is burnt. Wen shifting into d or r a loud annoying jolt is heard. Wat do I do? I Haf over 300k miles on d dash of my 5cyl 02 s80 Volvo.