Sewing Machine Meltdown

Recently I got the chance to go to FabricLand, where I found that cotton prints were 60%-70% off! The prints were absolutely adorable, and I knew that I wouldn't be back into the city for awhile, so I went a little crazy and bought a whole lot more fabric than I should have. So I get home and I am looking at all this fabric and I am at a loss of what I should do with it, so I pull out my pattern box and start looking through it for inspiration.
I finally decided to sew my daughter a cute and light little summer dress. It turned out even better than I had imagined!


Since the dress turned out so well, I was going to make a few more to sell at the flea market that I had a booth at last weekend....but the disaster struck and my sewing machine decided to go on strike!

I have absolutely no idea what happened to it or how to fix it. Basically, it stitches fine, but when I go over a seam or a wrinkle, the bottom thread doesn't catch. Then it keeps skipping stitches for 4 or 5, then starts sewing great again! It's soooooo frustrating! I have taken it apart and put it back together and fiddled with all my settings, and I have no clue what to do next.

Does anyone have any suggestions on what is causing this or how I can fix it?

My Singer is a basic model and by time I take it to the city (over 2 hours away) where I can get it fixed, it would prolly cost more than it's worth. I hope I can get it working because I defiantly can't buy a new one. It took some fast talking to justify my new Cricut Cake to my hubby and I am pretty sure he would not be too happy if I dropped another chunk of cash on a new sewing machine!