1991 Honda Accord RPMs acting wierd

Here is my problem. My 1991 Honda Accord is acting wierd and here is what is happening:

1: When driving b/t 35-50, my RPMs sometimes drop around 500 rpms or so and then go back up.
2: Sometimes when accelerating, my RPMs are running higher than normal i.E. When I am hitting around 35mph, RPMs are around 3000, and when transmission shifts they drop to 1500, which isnt normal and I am not pushing that gas hard at all.
3: Sometime when driving on the highway, 65-70 mph, my RMPs will sit at about 2700-2800 and then jump to 3300-3400 all of a sudden and stay there occasionally jumping back and forth b/t 2700-3400, which 3400 is higher than it has been in the past at that speed. It will sometimes run at 3100rmps at 65 mph now where as it used to run at about 2500-2700rmps.

This has all been happening within the past week and a half out of nowhere. I was wondering if this is a sign that my transmission is slipping, or if something else is going on with my fuel system, throttle, etc. Any help would be appreciated b/c I really can't afford to run out and get a new car.