Having trouble with trying to get rid of shitty communication habits.

I started my self improvement journey after I was with my gf.

I have noticed that if I don't make an effort, she starts getting upset. Very subtly asking me what's wrong, etc. nagging me.

One problem I have is that I want to change my vocabulary. I speak with a lot of slang and swear words in my home language. I make a little progress but then revert when I spend time with her.

Does anyone experience this? Does it change? My gf has issues, but I have yet to meet another woman of the same caliber - which is why I don't want to leave her