I think your trying run before you can walk (or flip before you can jump)
The best advise i can give is to practise on the trampoline so you can land them everytime and do them without thinking about the flip and even then i'd say go to a gym where there will be more people to learn from.
I HONESTLY think this is a stupid idea wait till your jumping is better and wait till you can flip and land it on the trampoline
Sorry for not giving you the answer you want but the last thing we all want to hear is that you broke your neck!