Distressed Mommy

I have a dilemma and , although I have been gone from my blog for quite some time now, I thought I would take a chance in asking for your advice.

I recently returned to work an I have loved it. i work 9-3 and for the most part that sounds perfect. However, things haven't settled as I thought they would. I don't get to cook or have as muich time with the kids. I am too exhausted to take night classes, so my degree is on hold, again. My son (he's 4) has had to be shuffled around between Mother's Day Out part of the week, a drop-in center that he loves and a friend's house. I think he is having the worst time adjusting and he seems to be picking up traits that I am not exactly thrilled about.
My daughter is 9 and it seems kids these days are warping into tweens early than ever.

My mom was a single mom and all I recall is her being very busy. Busy with work, helping her alcoholic sister and maintaining a relationship with someone she should have dumped long before she did.

I have less drama than that, but I do not want my kids to look back and feel I wwas too busy/stressed/exhausted to be there for them.

Should I quit and wait until he is in school full time to go back?