I know it is a lot for you given your commitments. I also know how important riding is for you and how little you take for yourself. I'd say sit with the idea for a bit and just make sure it is what you really want.

If you haven't been euthymic in years it would be hard to really know if it is a true euthymic state or some kind of alternate you've just never seen before. I believe you, but these things are tricky to sort out without giving it proper time. Patterns can only show themselves as the days pass. Maybe check in with yourself over a period of time and see how the idea settles.

Normally I'd say it's your money, spend it how you want... But you paused and came here to ask for a reason. There's wisdom in that. Trust it.