curved penis difficulties..

Trying to have sex with my girlfriend, when my penis is erect it’s an almost 40-45 degree angle downwards. I’ve managed to get it inside of her with a bit of difficulty missionary, but have had no success doggystyle or from her trying to get ontop of me (it slips out). I am a bit taller than her (6’0 vs 5’6) so that might be a factor? idk i just dont understand what isnt working