To quit or not to quit?

I've played football for the last 5 years and I most likely will be next year, however football is no longer my pion, I mean I enjoy playing and I enjoy being part of the team, but i despise the time commitment. I feel the bigger issue though is my positioning in football, for the last 5 years I have been a lineman due to being bigger than everyone else my age, however over the past two years I have grown around 5 inches and lost 20 pounds so now in my freshman year I am 5'10" and 165 lbs. It's not as though I lack the brains to be in a skilled position (all honors cles) or the speed as i was the 5th fastest person on our team including backs and tight ends (we don't have wide receivers in our offense), or endurance as I would finish in the top three of just about and conditioning that involved endurance, my school's football program basically wants you to be settled into a position by the end of your freshman year and i was once again a lineman. I just don't want to be lineman sized, as I refuse to put on fat weight to gain a leverage advantage, and i just don't have the build to be stocky and muscular. The other problem I run into is my father. he wants so desperately for me to continue in football, that he went so far as to say he would not help me as much financially if i quit. Not that it would be a health issue for me as I still participate in Karate, Swimming and Track, he just said that those aren't as entertaining to watch. Well I seem to have rambled far more than i had originally planned so I'll go ahead and bring this to a stop. All in all should I continue with this sport or not?