25f frequent back pains and spontaneous numbness in arm/hand/fingers/feet & toes! When I press on my lower spin above my butt crack it feels like pins and needles?

Sounds like nerve. Most likely condition would be a pinched nerve. The nerves that supply the feet stem from nerve branches traveling from the leg. The "pinch" could be from the back at its root, but it an also be locally due to musculature. Another thing to be checked is circulation because if blood flow is hampered to a an area, it can cause pain and reduce function in the nerves. Get checked properly.
See back specialist. Sounds like the problem is originating in back.