Don't know what make model reel you have. But here's some generic thoughts.
1. Check the reel and see if you have a drum brake. The drum brake is there to adjust how much force it takes for the drum to free wheel line out.
If that is too tight, then when you go to cast, the reel will be artificially "braking" or slowing down how fast the line will be let out. On an over head cast, that means a nose dive lure. On a side cast, when you are swinging your arm from right to left, again, the lure will go too far left.
2. With the reel set just like it is, put a heavy 2oz or 3 oz sinker on it and try to cast the same way you were. If with a heavy weight on it, your casting improves, then it is definitely the drum brake that is causing the problem.
3. I doubt it has anyhting to do with the line on wrong, hard to do that on a bait caster.