Girls only please please?

okay iam 21 and my girl is 18 we have been fighting alot now abut stupid stuff i love her but sometimes its hard to say whats on my mind other wise she gets hurt and i dont want to hurt her i love her to much but sometimes i feel like getting things off my chest so help me please she doesnt understand im not like the guys she dated im much more sweetier and romantic than the others and she doesnt like it