Actually I know it 'looks' that way but in reality it's a lot more flexible, especially at the moment with the teacher shortage (I've worked at Thai universities in this area and have had a lot of contact with schools). You definitely don't need a teacher license, a degree of any kind is sufficient to get a work permit. Also language schools are much more flexible about this, and there are loads (although the pay is terrible, even worse than in Thai schools which is pretty bad generally).
How about trying to get a job teaching English, or English online? You could get a TEFL qualification online. Apart from that - I'm very surprised to hear your embassy said that (is it Ireland?). Certainly the British embassy is offering loans for flights. I think they have a legal obligation to do that. Given the situation you outline, personally I'd look at a way to return 'home' with your son. I don't think there are going to be many openings in the holiday sector here for a while.
I’m not naive. I know it’s not strictly ‘legit’ as with so many things in Thailand and life. I know that many people in Thailand are on very limited means and to them paying an agent 1000 bucks is huge if it doesn’t work out. Fortunately I’m not in that position myself. It’s a calculated risk I have taken, pure and simple.