At end I think. Need some advise! please...

By

At end I think. Need some advise! please...
She has no drive nor passion for me anymore yet masterbates nearly every night

We have been together 12 years. We have 3 kids together and 2 years ago she got cancer from HPV and has had her lower region cut on many of times and then radiation . I'm a very passionate guy and love sex and making love. And now for the last 6 months I guess it hurts her for days after sex so we have it maybe you every month and a half. Almost every night if I'm laying there and she thinks some sleep she will start playing with herself but as soon as I move or open my eyes that she can see she will stop. And when confronted she gets very mad says you're sleeping she can't control what she does or sleep. We have had many arguments about it because I feel like I'm being lied to. Do we just need a splitter ways or does somebody have some advice I can try?