1. Though non consummation of marriage is a ground for nullity of marriage but it is very difficult to prove , more so, if the other deny this.
2. Rather I would advise you to fie suit for divorce on the ground of mental cruelty wherein you can mention this incident of refusal to have sex with you.
3. I think since you do not want her back then without waiting for her action you proceed to file a suit for divorce.
4. After so many years if she files case u/s 498A IPC that is unlikely to carry much wait and you should not get problem to get bail.
5. if you propose for mutual divorce then my reading is they would come up with hefty demand. So better avoid to make this proposal right now.