I really need some answers! why are my dental implants not holding down my bottom teeth?

So many reasons...: So many possible reasons: 1) was the bottom teeth (your denture or partial) made with correct occlusion or fit? 2) was the amount of implant adequated for retention? 3) what was a mechanism for retention on the implant (was it a bar, an o-ring, or a locator attachment?) 4) was the position of the implant correct for load distribution? 5) were the implants placed as parallel as possible?

A few thoughts..: I assume your "bottom teeth" refers to a denture. If you have only two implants, the attachments may have worn out (the "snaps" don't last forever), the denture may not fit well anymore, or something broke. This needs to be immediately evaluated by your dentist. A denture (or bridge) that does not fit will can damage the implant(s) and result in failure.

Implant Prosthesis: It could be related to mobility of implant fixtures, attachment mechanism wear or failure, occlusion (bite) or design with sufficient #/implants? Was this problem from the original date of insertion or did it just develop? Some issues are easily remedied ; others may not be. Your own dentist or a prosthodontist can examine you and evaluate the cause and discuss solutions.

Implant Issues: It sounds like you have implant supported dentures. Implants, even though made of metal, can break. It’s uncommon, but it can happen. Also, the implants or the attachments to the dentures might have warped, or the dentures were not measured for a proper fit to begin with. The best advice is let your dentist know so they will be able to repair the damage or readjust the fit of your dentures.