Logic anyone?

So, it's spring in Harlem.  That means two things: 1)the kids all have spring fever and want to be anywhere but in school. 2)I have a much more serious case of spring fever and want to be anywhere but in school.  The obvious problem with the latter is that I am an adult (still hard to accept sometimes) and I must be responsible.  For some reason this spring seems to be more difficult than usual.  I think it has something to do with the lack of warmth and sunshine.  So today after a difficult day at school I called my mom, hoping she could talk me off the ledge.  (and back in through the window in case that was unclear)  I complained my very familiar complaint that it's hard and I'm tired and frustrated and I don't feel like I'm doing any good and I'm starting to get cranky and I don't want to be that teacher.  

We talked for a bit about what I might want to do.  I keep thinking about other "good" schools where I could teach or even other cities, or grad school.  That's as far as I ever get in my dreams of a better life.  And this is where the irrational thoughts find their way into my quandary.  As soon as I start thinking about leaving (for reals and for good) I start to feel guilty.  Here's why.  I now understand pretty well the things that my students face on a daily basis.  They're certainly not the merry little problems that I had in high school.  I also know the quality of teacher that teaches in my school and schools like mine.  Granted, I have met some excellent teachers in the last few years, but they're the exception, not the rule.  Even the ones with good intentions don't have a lot of experience.  And they're not all good intentioned.  So this leads me to thinking that although I'm not an excellent teacher, (sometimes not even that good) I'm certainly have good intentions and can be an example for good in their lives.  So here's my question:  if I don't do it, who will?  Do I get that choice, or is this required of someone to whom much has been given?  And what if I do stay?  Will I spend the next few years getting tired and cranky for nothing?  If I give up do I think it's a lost cause?  Do I hope someone else will fix it while I go on with my life? 

I accidentally sound like a martyr, but these are all questions I want an answer to.  My mom thinks I've done enough and wants me to move on.  I wish I felt like that.