My gut reaction is that you sound like you're doing great compared to your postion a few years ago!! ((( ))))
But to address your financial concerns: First off, PA may not allow you to "go home". If dad doesn't agree with the move, you'd likely have to go through additional court proceedings possibly including a custody evaluation for which you may have to pay. Not to mention lawyer fees unless you are comfortable being a pro se litigant. This is a huge stressor emotionally as well as potentially financially.
You've got a low car payment, but how long is the term?
Child care
does decrease as time goes on and 2 years isn't that long, relatively speaking.
I understand the eating out issue if you are talking about weekday convenience. Picking kids up from after-school care and getting them to their extracurrucular activities doesn't leave a lot of time left for homecooked meals. Try to cook at home on the weekends. Make your crockpot your best friend. Cold PA winters lend themselves nicely to warm hearty crockpot meals.
Your pay
does sound low for a bachelors degree, but I don't know the COLA in your area of PA. The tuition benefit can be huge, if you plan on pursuing a masters. But given the age of your kids, it's not that big of a selling point for your kids tuition yet.
Even though your employer is not matching yet, can you start a small payroll deduction to the 401K just to get in the habit?
If you love your job, I think you should try to make it work. Lots of people are miserable in higher paying jobs that they hate.
Additionally, I want to touch on the emotional aspect of moving. Please take into account the effect this may have on your children's relationship with their father (and possibly extended family on the paternal side). I'm betting that you have already given this a lot of thought and chose to omit the details b/c they are not relevant to the financial aspect of the situation (and really none of our business either

)
Really, it sounds like you've come very far in the past 4 years and you should be proud of your accomplishments.