need help to walk again

Neuropathy after weightloss is pretty common. Some doctor's think it's related to crossing legs while sitting (which is why it's more common in women).
My sister had it pretty bad and her PCP thought it might be MS. He referred her to a neurologist, who quickly calmed her fears and diagnosed her with "slimmer's paralysis" and told her it was a temporary condition that would go away on it's own...which it did after a few months!

It is unlikely that your foot drop is directly related to your VSG. I strongly encourage you to continue to follow up with your medical team. If you aren't getting the answers you need from your current team, consider getting a second opinion.
From my encounters with patients who have it, foot drop is a musculoskeletal manifestation of a neurological problem. From a little digging, I found this link Spine-Health Foot Drop I consider Sine Health a reputable source and use them a lot in my work.
You say it started after a dull ache in your hip. On the above link, I see that it could be a result of trauma to the hip or pelvis. Any falls in your remote past? Also, look at the peroneal nerve cause: "EXCESSIVE WEIGHT LOSS" or even something simple like an ankle sprain.
Based on my understanding of foot drop, it is MANAGED and not CURED. So, you'll likely have some degree of residual foot drop forever. While we're all quarantined, there's not much in terms of aggressive treatment. But, here's what I would do:
1. I'd make sure I had supportive footwear and definitely something supporting my ankle. An ankle splint is best (behind the foot to hold the foot in position and keep from dropping). If you don't have that, I'd put an ace wrap or similar on it to help support the joint.
2. I would immediately begin some sort of range of motion and strength exercises of the ankle and foot. Ankle rolls (clockwise, counterclockwise, up/down). If you have thera-bands or something similar, I'd use those too. *YouTube is a wealth of knowledge and I'm sure you could find some easy-to-do exercises for home.
Disclaimer: my input is not meant to be taken in lieu of your personal medical team's advice. As a nurse, I cannot diagnose or prescribe, but I can tell you what I've seen and what I'd do if it were me. Good luck!

that doesn't sound like it would be anything related to your VSG surgery. Did you injure it somehow? I had that issue (foot drop and balancing issues) for several months after I sprained an ankle because the fall damaged my peroneal nerve (the main nerve that goes down through your leg). It did eventually work itself out, though - I had physical therapy for it which I think helped. I'm not sure what's going on in your case, though. If you didn't injure it somehow, I'm not sure what type of condition would cause that. If it IS due to injury, the injury could have been in your hip because that nerve goes all the way down your leg. My leg was pretty numb because of the nerve damage, and that's what was causing the foot drop and balance problems. Hopefully you'll be able to find an answer. I'm sorry you're going through this.