Brief Answer:
Probably diabetes, it should be ruled out through examinations.

Detailed Answer:
Hello,
Peripheral neuropathy is a result of damage to the peripheral nerves.
There are many medical conditions that cause neuropathy .
The most common cause at my clinic is diabetes.
Diabetes can be related even to other symptoms mentioned in your query such as weight gain,fatigue and anxiety.

I would suggest the following examinations:
- blood glucose level
-Hemoglobin A1c levels, which show the average blood sugar concentrations for the preceding three months

Meanwhile, I would suggest a healthy diet and exercises daily.
After the suggested examinations you can contact me again for further evaluation and treatment.

Hope I have answered your query. Let me know if I can assist you further.
Thanks.

---