Better call the embassy before applying- I have Spanish Citizenship and i was planning to apply from Madrid Embassy before - I called them and you have to provide more requirements than their website. I applied via Athens instead, having a Maltese resident card ( coz i was living/working there when I applied online ) 🙏
You have to report normaly every 90days at immigration office. If you've overstayed, you're looking at a fine of 500thb per day, up to a maximum of 20,000 thb. Go to an immigration office ASAP, explain your situation, and consider getting legal advice to handle this. 🙏