to refine my answer ... i said you're PROBABLY not allowed in. Being the dad of a Thai child gives you points ... but I think even with that, the numbers allowed in are very limited (200 foreigners a day maximum?).
Contact the embassy and stake your claim. Then hope.
You're probably not allowed back yet. The foreigners allowed are in certain limited categories. You would need to apply to the embassy in your country for permission to return. Don't hold your breath just now.
I think the secret is to go to your local immigration office and ASK THEM.
The problem with asking here is that what is right for Fred in Pattaya will not be right for George in Khon Kaen ... or Eric in Chiang Rai ... or Nigel in Phattalung .. etc. Every single office seems to make up its own rules.
well, I went with my partner. I have no idea what was said to be honest. I just kept being handed papers to sign or fill in. Whatever it was, it worked.
You shouldn't need any agents. But do go with an articulate Thai person to speak for you. I've opened 2 bank accounts (with visa debit card) whilst on 30 day visa exemptions.