Yes...
Many times lack of Vit
B12 can weaken the nerves and decrease libido, but it can't be a single cause.
Need more details for accurate treatment.
It can be well treated with counseling sessions and homeopathic medicine effectively and without any side effects.
Supplements can be added later.
You need an expert Sexologist who is a good homeopathic physician and psychologist.
Next Steps
I have been working as a Homeopathic Psychiatrist, sexologist and Counseling psychologist for the last 17 years of experience. You can contact me through an online appointment for further assistance.