Could you go back to your current firm and still take them up on the offer of a permanent job? If the answer is no, then there's no point regretting it: just go forward with your plans. Even if the answer is yes, you have an associates, CAD ability, IT/programming skills, a history of employability and an established relationship with a temp agency that can get you work. That puts you in a strong position already, and you obviously very much want to get your BS in architecture so I would say "go for it" - you sound like you would regret not doing it. Presumably you can pick up some freelance/part time work to help finance it?
The "2 hours away" comment makes me a bit concerned about whether you are planning a long commute, but if you are reading this forum you know what a bad idea that is.
By the way -
1. As your firm offered you a permanent job, they obviously thought that you were a good fit for their workplace. If you ever have concerns about how you are perceived by your managers as respects "fit", you can always ask. But it is worth remembering that you don't have to drink the Kool-Aid just because you work somewhere - you are allowed to retain your independence of thought regarding your employer.
2. The $3 an hour "pay cut" would probably have been offset by the benefits (health, retirement) etc. that are usually offered with a permanent post and which you don't get as a temp for hire. But once you have an offer you can always try to negotiate it upwards.