Overwhelmed!

This past week (the last couple of weeks really) have proven to be extremely overwhelming. I feel like I have way too many things going on in my life and need some kind of escape. I've been working lots which is good, in the sense that I'm making money, but not so good b/c I need time to finish up my chemistry course which needs to be done by the end of July. I know that God is my strength in all of this and that w/o Him it truly is impossible...I know this...but yet why do I find it so unbelievably hard to just rest?!? Rest...what a word...I'm not even sure that I know what it means anymore. Sure, I rest as I sit in front of the TV and try to mask my worries by zoning in on something else or by just being lazy, but resting in God...how is that possible? How can I just allow myself to not worry about the fear of not accomplishing these things that need to be done? Why am I so fearful in the first place anyways...whatever needs to be done, God will be sufficient in these things...He is the source of sufficiency...He IS sufficiency...
But my unbelief, amidst my belief, seems so rampant...God please help me in my unbelief!