Sounds like the clutch could be slipping. Is it really hard to get in and out of gear? If so I would probably point my finger at the clutch. Have you had high clutch engagement? A good test to see if the clutch is slipping is to put the car in 3rd gear from a stop and let the clutch out, if the car just sits there and does nothing and doesn't stall then your clutch is probably slipping. If the car jerks forward a bit and then stalls then your clutch isn't slipping. Hope this helps some.
