@Br***
I would look through your passport and see if you have any room at all on other pages. That page on the left, for example, definitely has room for at least one entry/exit stamp, on the top left.
If you do, and I imagine you do, I would then do a border run to Mae Sai/Tachileik. I have in the past got both the Burmese and Thai immigration there to REALLY squeeze stamps into corners of pages, where even some of the stamp was off the page.
Point is- you should be able to do a border run to a country that does not need to affix a full page visa, as long as you can squeeze in four stamps (exit Thailand, enter Myanmar, exit Myanmar, enter Thailand) somewhere.
This is presuming you haven't done two border runs already this year.