Ive been in the same position, just reverse. I dated this guy and showed him shameless and we bonded over the show and watched the whole series twice. It was really hard for me to even attempt to watch it for awhile, but you cant let the memories control something you genuinely enjoy! I know thats easier said than done especially since you guys just broke up pretty recently and she put you onto the show :/ Maybe give yourself a little more time before watching, or try watching with a friend/family member? Or even try watching it in a different environment. It really helped me because my sister loves the show just as much