Things to pay attention to:
- Your BMR (Basal Metabolic Rate), this is the amount of calories your body needs in a day just to exist (think in a coma, alive but not moving). BMR drops as we lose weight and as we get older. So it's something that should be calculated and monitored with WLS. https://www.active.com/fitness/calculators/bmr
- Your water intake, you stated that you try to hit your protein targets, which is great, but your body just cannot break down fat if there isn't enough water.
- 3.5 miles 2x a week isn't near enough. The minimum basic goal is 30 mins of targeted physical activity EVERY DAY, for WLS, it really should be 60+. Also, running is great, but running will **ONLY** lean out muscle, if you want to burn more fat minute to minute, you need to be building muscle mass.
- Without seeing (or being a doctor specifying in plastics) It's entirely possible to have 20 lbs of excess skin
- Have you had your body fat measured? I'd be interested to see what your lean mass to fat mass numbers are. I'm 5'9 currently at 258.9, 37.2% body fat, My scale calculates that I have 162.7 lbs of lean muscle and 96.2 lbs of fat. I'm shooting for 200 lbs, so if I do make it to 200, I'll still have 37.3 lbs of fat that *could* be worked off if I really wanted to, this doesn't count skin weight though.
If you are really stuck/stalled and frustrated, try re-doing the pre-surgical diet to "reset" things. I also highly suggest starting to track your intake and burn again, if you are burning more than you are taking in, you *WILL* lose weight.