I want a girlfriend. Just a short term thing, nothing serous kind of a two year fun time( bad usage of words, Also have been sort of single for three years almost).

I have had a problem moving forward lately. Part of me says if a relationship isn't going to last then don't bother. And I also tend to pick out differences and make excuses as to why I shouldn't date a girl. ( note: I can hook up no problem when I want to)

Example of a a girl I am interested in, and who is very clearly into me as well:

Girl who works at my gym: Really athletic, study's very hard at school, two jobs very responsible and great head on shoulders, good relationship with family, amazing cook, clean cut.

And Here I am thinking about me:

Drink often and heavily, almost chain smoke,Works out to get laid, slack hard in school, no job( don't need one during school since I work rigs), no responsibility.

So I am a little worried about her finding out about this stuff and how she would feel. I feel like my "habits" so to speak would ruin the relationship.

This is one example of a few, I do have other options, and I can always find more. I hope I worded this properly I have been thinking about it a lot lately. I am sure how to say it to my friends, they won't put me down but would't give good advice.

I guess the TLDR is that I have been having a hard time getting actually close to girls lately for various reasons... Hope this is legible I just had to spew this out to some one. Thank you if you made it this far.
Edit: Bonus question: I can't word this any worse than it sounds: Is it ok to "fake it" in a relationship for a while? I kind of feel like it is ok as long as both parties are happy.