I tried that with a cold shower and I literally could not fight through it, do you have any tips?
Choose a time period to take a shower for (like, 45 seconds), set an alarm, and instead of fighting through it, get in the shower, turn on the water, and helplessly give up, collapse under the cold water, and let yourself out when the alarm goes. You only have to do this once or twice to convince yourself you can physically survive the cold water; from there, resisting it should be easier.
Note that this is a little bit extreme.
You should probably read the Anti-Akrasia Tactics Review, if you haven't already. There's lots of useful stuff there, and if it works for you but you haven't read it...
You should totally go read it, implement it, and not come back to this thread until you've internalized your favorite tricks.
Feel free to discuss outcomes here.
Did anything work for you?
Is there anything that should be added?
Note: this is basically a "bump", but I suspect that it's a worthwhile reminder. Downvote me if I'm wrong.
P.S. I'd actually really enjoy feedback on this.