For about a year, my daughter worked about 24 hours a week (she was studying) answering phones at a hardware store, a very large orange coloured one. Each outlet had a pair of phone people, and the job went to teenagers because no one wanted it. She didn't mind it, and said while it was busy, time flew.
Because you are young and don't have the education yet, there is a shortage of work from home options. It's hard. Even call centre things need you in there. Plus I get the sense you're in a more rural area, right?
Still, I'd explore customer service type things. I know nothing of horses, but would there be any supply type places needing a good voice to answer questions?
Do you have more than one language? That would open doors.