I think everybody have memories or feelings related to songs. It's something very natural. The problem is when you despise something you like because it was playing at a bad moment. I hate that , so I try to remember the reasons why I like that song first and forget the bad memories.
I always go to college with my cd player on , and although I like to go to there , everybody have bad days or stressful days ,so in that cases , I use my music to relax and try to feel better and it usually works!!
So, try to use your music on your way to school to forget the bad feelings. I use to concentrate on the music and isolate myself from the noise and the stress of the city.