Nobody likes losing trades, but successful traders before putting on a trade fully accept that each trade has uncertain (random) outcome and can turn out to be a losing trade.
Those traders who don’t trade of this mental state of acceptance, won’t make it long term. They just want winners, and are fearful of taking losses. Losing trades are part of the business, that’s why risk management is critical.
I have bad news, to become a good trader, you must become very good at accepting losing trades. Forcing discipline is just a temporary band aid. Discipline needs to be automatic and effortless, not forced. You cannot fix lack of acceptance with discipline, at least not long term.
It’s like breathing, you cannot just 'breath in' all the time and being uncomfortable and fearful of 'breathing out'. Just as 'breathing out' is part of the living process, so are losses part of the trading process.You need to accept that, and become obsessed with risk management.
Work on acceptance and other things like position sizing, reliable edge with positive expectancy, etc., so when you trade you learn to automatically flip into a detached perspective so you can observe yourself from a third person perspective (instead of being fully associated with each trade).