You are allowed to want better sex and his defeatist, lazy, selfish, and jealous, attitude to his issues says that he doesn’t care about your pleasure at all. At your age, you should be having lots of wonderful sex and working out what is good for you but I’m afraid you are never going to get that with this man, not because he can’t, but because he couldn’t be bothered enough about your pleasure to try. He is unlikely to change with marriage.