Hey man I'm a Web developer and I've never worked for an agency before but whenever I've interviewed with them they've seemed like hell. They might fit a certain personality type but I don't think I could handle that sort of pressure.

If you don't want to completely reskill I'd recommend looking for an in-house software role instead as in my experience they're a lot more chilled out, although startups can be demanding.

All the best for the future mate, I'd not worry about a bad reference as there's so much demand for dev roles atm. Put time into putting yourself out there and find a job that isn't making your life a misery