one more correction, LZ:
if you stay in U.S. less than Three years after your first come,
no matter you are J1 or H1, tax exempt is valid.
Agree with macula,
if your boss just pushes you to work (push too hard), and all the other
parts are not bad. You had better stay.
But if you can find a better university for your next job, you had better
leave. Anyway, postdoc in a small university does not help a lot for your
future caree.