craftgrrl | help, working with an OLD singer

...I put new thread in the machine, a heavier type thread than what I have used lately. I am not skilled at knowing EVERYTHING about sewing.

I do know I threaded it right and the bobbin is in right. My problem is:: the thread from the needle is leaving huge loops on the bottom hence the bobbin thread isn't working to hold any stitches in place. I am not sure what happened to change the "settings" of my machine since it worked fine before I switched threads. Please give me a hint/ heads up or ANYTHING! I am extremely frustrated here.