I think I just killed my Homey

Had the same Issue this Year. The Power-Adapter/Power-Plug was broken.

If you are using the original Power-Adapter/Power-Plug and original Cable try an other one with this specifications (got them on my Issue from Athom): Please make sure the output is 5V and at least 2A (2000mA).

If you are using an other Power-Adapter/Power-Plug you should switch to the original that came with Homey.

See also here: