Well, I’m making a pair of fingerless gloves in stockinette stitch and I’m fairly new to knitting. I just dropped the last stitch of a knit row off the left needle and now I’ve just got a loop hanging off. I’ve read that I can just put it back on the left needle and continue knitting, but I’ve actually got to cast on 5 stitches at the end of this row. Any idea’s? For weeks I’ve just been starting all over when I mess up, but I’m so tired of doing that that I actually cried from frustration. Please help.
These are knit flat? And what happened is that the last stitch on the row fell off before it was knit and is sitting there as a stitch loop? Is that right? If so, yes, just stick your left needle back in the stitch and knit it. Then proceed to do the cast on however you intend to do it.
Ideas for the cast on if you don’t know what to do: You could use a Single Cast on as given in the videos. You would do that at the end of the row, just throw 5 more stitches onto the right needle at the end of the row. Or… turn and use a knitted cast on, or cable cast on. This will, in effect, put the stitches at the end of the row, since the end of the row and the beginning of the next row are the same place really.
Knitting can be frustrating sometimes. It isn’t always smooth sailing and totally relaxing. We all make mistakes and have challenges. Take a break if you need to. It will help you if you can learn to fix mistakes, but in some cases that means tinking back or ripping back. There is not a quick and painless fix for everything, even for the experienced knitter. Hang in there.
Are you knitting flat or in the round?
As long as the working yarn is still through the stitch just pick it up and keep knitting. If it’s a loose stitch and the working yarn is coming from the next stitch pick up the loose one on the left needle and then knit it.
Even knitters who’ve been knitting a long time make mistakes and drop stitches so you’re not alone. Learning to fix mistakes is part of the process. 
We have some videos here for fixing mistakes that will probably help you out at some point.
http://www.knittinghelp.com/videos/knitting-tips