timesick
Just like homesick, except it's a longing for a different time than the present.
1) All this homework is making me timesick; I wish we could just go back to kindergarten when our hardest assignment was coloring inside the lines.
2) I'm timesick. I wish I could just fast forward to after graduation.
2) I'm timesick. I wish I could just fast forward to after graduation.