Your relationship sounds like a recipe for disaster. Why do you keep arguing? What do you get out of being nasty to each other? Being in love is supposed to make you happy but you spend your time agonizing and, frankly, enjoying the agony. At some point, she is going to get tired of all this and want a reasonable and happy relationship and you won't be the one she wants it with.
God is not an agony aunt. A relationship with God is long term and needs work. If you don't like Christianity, then choose another religion, but the answer is still the same.