I just recently left a bad situation....my ex-fiancee was a dick who had no job, mooched offa me and was a complete l00ser! He meant EVERYTHING to me...I would've done anything for him and I did...
I met Shawn, who is like you described, is the male version of myself, me and Shawn are perfect together.....
I sat down with my ex and told him(thru tears) that things weren't working, neither of us were willing to give, and we were never going to get anywhere...
It doesnt make you a bad person to get out of a dead end situation, my ex-fiancee owed me more than just 2 grand....he owed me about 2 years of my life

(and about 5 grand)
If you are unhappy where you are currently GET OUT OF IT!!!!!!!
its not fair to YOU or him to string along like nothing is wrong!!!
I didnt care about the money, when I finally had Shawn, whom never met my ex- and knew only what he managed to get me to say, tell me that without even knowing me well, he knew that I was a very depressed girl, the next day I sat down with my ex- and broke it off.....
you have to take care of yourself!!! you aren't doing the current guy any favours, and it sounds like you aren't doing yourself any either...
as far as the new guy, shawn started as that, just a great guy that was fun to hang out with, i could talk cars with, etc..... we slowly let ourselves 'fall' into love, neither of us wanted a commitment, and needless to say I was terrified of another dead-end relationship, now we have made a commitment to each other to try our hardest to make this relationship work, we feel very strongly for each other...and I hope to marry him someday(but don't tell him that, he wants to wait a few more years until the 'ring'

)
good luck with your decision...its a very hard one...that only you can make for yourself!