I do a lot of my jeans shopping at TJMaxx and Marshalls because the stores are close to home, their stuff is inexpensive and, most importantly, I can usually find my size there. Lately though it seems like the only jeans in my size are Vigoss jeans. I've never heard of the brand and the jeans look kind of cheap and shoddy, like they were made in a third-world sweatshop. I need new jeans because I wear jeans all the time (unless I'm schlepping around the house in baggy sweats) and since I've lost more weight quite a few of the jeans that used to fit me are getting sliding off loose. I don't want to buy jeans that are going to sag and bag after one wearing because their quality is so poor, but maybe the jeans are better than they appear and only seem cheap because they were pre-treated to look old and worn.

Any insight would be much appreciated.

From a google search, vigoss is one of those department store brands. JCPenny and Kohls and such.
From my experience vigoss does use thinner, lighter material, which might be nice when its new (i work in a thrift store) and ive seen a similar problem to what you are describing. The material just doesn't seem very durable, but i think thats just the style of the jean. Perhaps it would be worth it to travel a little further to find more jeans, because your stats seem like you are a size that should have tons of amazing clothing out there for you, even if you have to get the length altered a little bit