Tips to combat the rationalizations and mental gymnastics?

Literally every comedown and 1-2 weeks following I am filled with shame and regret. I swear off it and easily abatain for a couple months. Its when I am finally feeling happy and strong is when that I start rationalizing. "Its not that bad because I use in moderation", "Ill force myself to eat and sleep to reduce harm", "Ill only stimfap for a couple hours then use it to do that task ive been putting off".

I believe the lies I tell myself. Even the rare occasion they are true I still regret it. I know in my heart I will regret it before i go into it.

I find it very easy to moderate my use but very difficult to quit for good.

Has anyone found psychologial techniques to overcome these mental gymnastics?

Background: 19-24yo heavy adderall abuse for "utility" during difficult technical college program while also working to pay the bills, thought i "needed" it but in retrospect i should have just been more disciplined or chose a different path, slid into stimfap addiction at this time, grew to hate the drug and its toll, stopped when i graduated, took a long fun trip and then moved away and never renewed my script

Mostly recovered but not not quite the same joy, motivation, and excitement as before i started. Hard to tell though, could just be getting older, other factors in life, or inaccurate perception of how i felt before. I worry the missed sleep alone did permanant damage.

28-31yo Got introduced to meth. Been using it for three years with 2-6 months between uses and no bingeing. Its basically just a stimfap/chemsex addiction now. I use meth exclusively for that purpose.

Its starting to engrain fetishes in me that persist when i am sober, that id prefer not to have. I have had instances of erectile dysfunction when sober that I suspect are porn induced. Im generally unhappy and wouldnt be suprised if its because I nuked my dopamine system. I can moderate well but theres always the lingering potential to spiral into life ruining habit.