You're chosen by the spirits or gods to be a "shaman". Typically in proper traditions (and since you have pretty good blood levels of Blackfoot, I highly suggest you start with speaking to a Blackfoot council/medicine man/etc) when we're chosen by the spirits to go down this path, we suffer greatly. It's called shamanic sickness/spirit illness, and it can be very extreme, often causing the death of people close to us or simply ourselves by trying to run away.
But you need to get vetted by an older, experienced shaman - again, I very much suggest talking to a Blackfoot council. There are lots of resources for blackfoot indigenous people online to gather and share knowledge amongst themselves so it doesn't get lost from the colonization.