Agents are not regulated in Thailand, and are almost always used as a backdoor bribe to an immigration office.
I would immediately contact the visa agent and try to get a screen shot of your valid extension of stay as proof that it's been submitted, and the passport wasn't lost or stolen.
IF they can't do that, I would assume they did not acquire the one year extension of stay based on marriage, and you are on overstay for about 8 months. I recommend contacting your embassy and get a new emergency passport. If you aren't scared about contacting agents (which you aren't), start contacting agents, let them know your situation, and see if there's any way for them to remove the one year ban for being on an 8 month overstay. I would expect a lot of money to be required though to prevent that one year blacklist (100K THB or thereabouts?)
See
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for the overstay regulations