Venting my frustration...

Recently I've been wondering if the path I've chosen for myself is indeed the one I'm meant to take. These past few weeks of school have been physically and so emotionally draining that some days I feel like all I want to do is break down and cry or wish that the truck coming down the street at me would just put me out of my misery. Is this normal?? I mean this is only second year of my program and if already I'm feeling this way, what will become of me next year or the year after that? I wrote a quiz today and I'm pretty sure, almost 90% sure that I screwed up big time. That just sucks...second quiz of the year on EASY stuff and I'm already stuck. Everyone seems to know so much more than I do or at the least know what they're doing while I still can't seem to get myself on track. I WANT OUT...I WANT TO GO HOME...NOW!!!