You are describing the classic, normal airplane behaviour. You do have a trim lever on elevator. Learn to use it. If you can, go for a flight in a full size at your local pilot training school, and just see how much trimming the full size guys do, you will be surprised at just how much is done. there is a trim for takeoff and climb, one for cruise, another for descent, and another for just about every flap position you use. Models and modellers are lucky, we have one and just put up with what happens at other times.
Evan, WB #12.