I think it's more important to participate in activism of an organization that doesn't perfectly match your ideology as long as the actions themselves are good, than it is to do nothing and remain ideologically pure

If that's where you're at now, that's where you're at. It sounds like you want to do more, but haven't figured out how to do that yet. I think the important thing is to keep looking for and open to new ways to improve and do more (joining an org would be a great next step), but don't be too hard on yourself for not being where you want right now.

Just keep doing what you're doing, keep that recognition that there's always room for improvement, and that not being perfect isn't a failure in and of itself.