Do I drop her?

I’m 20 and have a baby and a fiance well I have a friend she’s only 18, no kid or anything but has her first boyfriend. Well me and the friend live a little close about 20 minutes well all the times she asks me for rides to her boyfriends which his house in an hour from hers so I’m basically driving 2 and a half hours everytime and it’s just very inconvenient. If I tell her no she ghost me and gets all mad at me and won’t talk to me until she asks again and I say yes. Today I asked to go garage saling before I went out this morning she’s like well I’ll go if u drop me off at his after but it was 40 out the way so I said no I have to give my baby a bath feed him etc she has ghosted me since. My fiancé says I need to stop talking to her.. she’s been my “friend” for 5 years and hasn’t acted like this till she got this boyfriend and he cheats right in her face sending nudes to other ppl etc.