Having been just diagnosed with vitamin B12 deficiency I have been reading up on it. Some of the symptoms are tingling and numbness in the hand and feet, muscle weakness, and confusion. And it can be caused by having taken Metformin for a long time. So that seems a possibility.
If you would rather not speak to you doctor, then you will need to find another one. Even if we could accurately diagnose you through posts of a forum (despite very few, if any, of us being medically trained or licensed) then you would still need to see a doctor for prescriptions or access to other treatments. So all we would do is delay the inevitable.
Maybe, though, you could speak to a pharmacist first if that will make you feel more comfortable. Whilst they may not be able to help you directly, they could rule things out and make suggestions for what it may be in referring you to see a doctor. That way, when you see your doctor the pharmacists's assessment may make you feel more confident
But what you are describing is a medical problem and it needs medical attention. If it is B12 deficiency then it can be easily treated with B12 shots to build it back up. Though if left untreated it can cause permanent neurological damage, so is not something you want to ignore or self medicate with weaker over-the-counter vitamins.