I smashed my fingernail by my car door. my nail turned black. my thumb is swollen and tingly. what should i do?

Ice down every few hours . If thumb swelling stays for a few weeks or more, then an xray may be necessary to ensure you have not broken the thumb

you have a subhungual hematoma beneath the nail and it should be drained to relieve the pressure reduce swelling . Heat a paperclip in a flame till very hot and use to burn through the nailplate to drain the hematoma