Is there a link between low folate levels and physical symptoms such as loss of sex drive, and hand tremors?

Could be. Folate is essential for blood formation and neural function. It would be imperative to get tested for B12 and folate, as it is not safe to take folate supplement in the presence of B12 deficiency.

Low folate does not cause tremors. But appears you may have additional issues besides your folate level. Discuss your symptoms with your doctor, evaluate sexual hormones, endocrine function, especially thyroid. Some medications could cause tremors, but a familial history may be key.