I think you’ve already got a lot of advice related to the mechanics of saving money (401k which has withdrawal penalties, maybe an IRA for greater friction, etc.)

On the emotional management / discipline front, I’d suggest also exploiting the similarities between personal finances and healthy living. If money is particularly painful for you, try forming simple habits like going on a 10 minute walk each morning, or eating healthy 1 day a week.

Small actions like that will help you prove to yourself that you can make changes, and you can ride that proof emotionally to make bigger changes incrementally over time.

An example would be 1 day a week of not eating out, which becomes a $10 per week saving habit, then moving to 2 days and $20.