I doubt that you bricked the unit. See https://www.cisco.com/c/en/us/support/docs/unified-communications/spa3102-voice-gateway-router/108734-pqa-108734.html .
Pick up the phone connected to the Phone port. Dial **** (ignoring whether you hear dial tone or any error tones). Do you hear the “Llinksys configuration menu” prompt? If so, do a Factory Reset as described above. After the unit has reset and finished rebooting, enable the Wan Port Web Server, then use option 110# to hear its WAN IP address. Open your browser to that address and set up the SPA again, from scratch. (This assumes that you computer is connected normally to the router, not to the Ethernet port of the SPA.)
If dialing **** doesn’t get you the prompt, unplug all cables from the SPA except the Phone port. Plug in only the power adapter, wait one minute, then pick up the phone and try **** again. If still no luck, report what the SPA indicator lights show.
There are several gateway devices with one FXS and one FXO port, including Linksys SPA3000 (very old), Obihai OBi110 (old) and OBi212 (current model), Grandstream HT503 (old) and HT813 (current). These are all very similar to what you have. There are also many professional gateways with four or more FXO ports. You’ll also find cards with one or more FXO ports that plug into a server chassis, rather than connect over the network. However, unless you are convinced that your present device is defective, I don’t recommend jumping ship yet.