Had a power outage about an hour ago, and every since it came back on, I haven’t been able to connect to HA.
I have that a lot too, every reboot of the host, HA has issue starting up. Luckily I have an UPS, so power outages are not a big concern. Anyways, can you connect to the machine? Do you have HA running in a virtual machine? If so you probably can connect to it. When you do and you see that HA did not start you can type the command ‘login’. Than wait for it to start. That will always help me.
If you run on a dedicated machine, connect a monitor and a keyboard (and mouse) and do something similar.