Straight as twisties....
I do the same thing as you, yet I don't call it a problem, I bowl right handed and finish on my right foot as well.
I do the because of a handicap (disability) I got when I was very young, I too when I first started bowling tried to alter the way my feet when, but I in the ennd gave up on working on my feet and started working on the things I could fix such as timing etc.
Anyone who knows me and has watched me bowl knows that my balance isnt perfect, but I make up in flaws with my will power and determination, I was considering giving up bowling at the end of last year if I didnt achieve the one goal I REALLY WANTED, that was to be in the Central New South Wales Presidents Sheild Team.
I made the state team (CNSW) this year, in a very tight situation because true ability and grit got me over the line (lets not mention the 6-7-10 spare) and I say to you dont look as it as a problem, if you score well sliding on your right foot, then dont stop. You can also get very good at bowling on the 'wrong foot'
Dont give up, dont fight it, just go with it, and bowl as well you can!
Goodluck!!!