I've done knit tops same as sewing grandma, in fact if you have a serger it's real easy, just make sure you don't do it too small!! Course then you just have to lose more weight
. I have also done a few sweaters, and those I have done just on my sewing machine, with a longer stitch, same as for the knits. If it turns out you have to do too large of a seam, you can always zigzag it then cut it. Press them carefully, with a light touch, seams only! I've done work scrub pants, course these are ones I've made originally, so I take out the elastic on the waist, sew the side seams, then redo the waist. Jeans, no way. I did try once and ended up tossing them. I think your idea of hitting the thrift shops would be good, in fact, take in your larger things that don't fit, that way you can't grow back into them! I did that, and it's worked for over a year for me. Good for you on your weight loss and getting more exercise! You deserve to get a few new things, even if it is a paycheque at a time. How's the work situation, talking about paycheques?