Need advice for cutbacks

Hi I'm riding a 7'4 funboard and I'm currently trying to learn cutbacks. I have been surfing for about six months and going about 1 time a week. I'm trying to learn cutbacks but whenever I try to cutback I just bury my rail and fall. I'm not sure if I need better waves or need to do something else because lately I have only been able to go on small weak 1-2 foot surf. Any advice would be appreciated.