ItIsAsItShouldBe

I received offers from three schools. One is the top school in the field (where I also happen to have been working), one is an up and coming program, and one has lead the way in my area of interest for a while but potentially fading out in the future. Due to pressing deadlines of accepting funding, I accepted the top school. I am now having some major "What if's?!" that are compounded by work stresses and an offer to extend my decision on funding from the up and coming program. Since I already submitted my decline to the school itself, I'm guessing I'm stuck where I am, but I am now freaking out. Thoughts? Anyone else living in regret city?