I had a Failed FUE. Should I try BHT from my beard or other donor area? Or could FUT work?

It is best to follow up with your doctor to understand why you had a "failed" surgery.  If you are not confident of your doctor's abilities then you may want to see another doctor for a second opinion. 

I believe you should go to the clinic that performed the failed transplant and then go to verified experienced clinics to consult your situation. before doing BHT, etc.

Beard area may be used as donor.The most outstanding reason for poor growth and ineffectual  hair restoration results is insufficient number of viable graft placement as a result of intra operative  damage of follicular units ( during insertion or high transection rates during harvesting, long time of grafts out of body, dehydratation, poor FU storage conditions like high room temperature and storage fluids etc.)If you  are not satisfy with  result of your first operation, would better to check those parameters and think about to plan a second HT to fix the problem.

Your best chance to get a good result is to consult a physician member of ISHRS.org for a proper analysis of your situation.

It would be extremely unusual for only 100 out of 2355 grafts grow in the hands of a reputable surgeon.  Before considering any more surgery you need to find out why the first procedure did so poorly.  Have you been back to your surgeon and discussed this?  You may need a more in-depth exam and possibly a tissue biopsy to see if there is some underlying condition that just wasn't apparent.

You need to confront your surgeon with the failure and ask your surgeon what went wrong and what he/she will do about it. I take full responsibility for what I do and am fully accountable, so should your surgeon be.  You need a good assessment and don't treat yourself, find a real expert to help you through this difficult time