Get well soon. I too have gotten really sick. Only getting better now and can’t sleep due to sleeping in bed all week.
I have read earlier in a few posts that it is a little more difficult to get the extension now without a good reason and people waiting the last minute are getting the 7 day stamp to leave the country. If you plan to stay here for at least a year longer I’d say to convert your exempt visa and enroll in a language school or a sport.
From my understanding, a sin sod is based on whether the bride to be has been married in the past, has children, eduction level, job position, status and age. Sin sod would also show her family that you are financially stable and can take care of their daughter, it is also a form of exchange in taking away their daughter and her duties in the family. Sin sod is truly what you can afford, it is negotiable as everything else in Thailand. There is no expected amount, but it is entertaining for the wedding guests to see how much you will be giving (especially as a foreigner) .. they expect more. most of the time if her family is good, you will get all of it back, most of it, half or some as a wedding gift.
Quite honestly, according to your post, I think your gut instinct is telling you something as I dodged a bullet myself. Though I wouldn’t want to assume completely with one post as I don’t know your bride to be’s status. If you have any questions, feel free to send me a friend request and message me.