you have done 2 land border runs this year, on February and April, so you cannot legally do more land border runs. You can do it by air though, but your entry entirely depends on the immigration officer at the airport.
Go out to the nearest country via land border again.
Extend again.
Time to buzz off by air and try coming in again. Keyword: TRY.
You can only go thru a land border twice in a calendar year (read: border run), unless you are from a neighbouring country. In your case, you have 2 months left.
Come in 30 days, extend at immigration 30 days, get out of thailand from the nearest border and come back in again 30 days, extend at immigration again 30 days, get out of thailand from the nearest border and come back in again 30 days, extend at immigration again 30 days, then back to your country of origin because you have used up whatever permitted in a year. Most probably gonna get questioned when doing this too often.
The problem lies with your embassy, they do not understand the meaning of an emergency passport. Embassies are there to help their citizens, not fuck shit up for them when they are in trouble.