This sounds pretty normal to me, in the conditions I ride in you can't just set your edge and ride upwind forever. Every piece of chop you hit slows you down and you either need to work your kite, or do what I do and just let off your edge for a second or two.
It's not really a big deal, just keep riding and you'll get the feel for how much speed you need at various angles. It's not even really like you need to know "what angle to ride at" or something, every time you ride you'll have a slightly different amount of power, slightly different current, slightly different amount of chop, etc etc... you just need the muscle memory and experience built up to know how hard to dig your edge in under which conditions.
Just keep riding