I know it says that it's a "Heavy Duty" machine, but it isn't. You can't sew heavy fabrics on a Singer with a plastic bobbin basket. You can't use a heavy thread on that machine, either. Even piecing a quilt is a stretch for that machine. They jam. That's what they do best.
You'd be better off replacing it with an old, metal Kenmore with a front-loading oscillating hook (serial numbers starting with 158 are my favorites). Get one with built-in stitches, not with cams. Look for a standard low shank presser foot, not a super high shank. I can usually find them at the thrift store for less than $30. Here's what they look like on Google Images:
https://www.google.com/search?hl=en&...mg.3n15-ThIdOI
Don't put any more effort into that machine. Use a vintage Kenmore until you can save up for a better machine.