I am older than older and I still have issues with fantasies trying to invade my brains. I thank Hashem for keeping me in the game and allowing me to still be involved in this holy journey. But we need to realize that the only reason Hashem sends us these nisyonos is cuz it's our mission to ignore them. And so we just need to keep on truckin' as they say. Main thing for me (an for those who relate) is to accept that this is my situation, and to make the best of it.
When Harav Meir Shapiro zt"l (founder of Daf Yomi) was on his deathbed, he had his talmidim dance and sing. When they noticed his matzav was getting worse, they were getting concerned. R' Meir couldn't talk anymore, but he motioned for someone to bring a pen and paper. And with his last kochos he wrote 2 words: "Rak besimcha" (only with simcha/happiness).
So no matter how old you are, and no matter whether you think your life is slipping away, "Rock beSimcha" (yeah, "rock" with simcha).
As Reb Nachman teaches us in his famous piece: אזמרה לאלקי בעודי
I will sing to Hashem with whatever little amount of righteousness I still have.
עוד מעט ואין רשע
The glass is never all empty, so just concentrate on your good parts and keep on improving.
[Thank you for listening. I needed that.]
Hatzlacha
MT