I've experienced several regressions in potty training since I've had Mandie. "They say" that yorkies and small dogs are harder to house break. I suppose they say it for a reason.
I am gone to work at least 10 hours a day, 5 days a week. Sometimes, I have to work later depending on what's going on. I close off all carpeted areas in my house and 90% of the time, Mandie will use the potty pad. The times she doesn't, it is poo and I really think that she starts on the pad and just walks off as she goes.
Since this was a drastic change for your little one, I would recommend an xpen set up. That way, you can put her bed, food, water, toys, and a potty pad in there. She won't be able to just wander all over the house and potty where ever. I definitely would NOT crate for that long of a time. Just start back with the training when you are at home..like from new. Praise heavily for going in the right place and correct when you see her going in the wrong place.
It's a long process. I've never had a dog take as long to potty train as my Yorkie. At 9 months, it is still an ongoing process. Every so often, she'll just go anywhere and I get so confused. I think that is her secret plan..to keep me guessing. lol
Hang in there, be consistent, remove any obstacles to success that you can (like take away free roam until it gets back under control). I have to block off my carpeted rooms every few weeks...who knows why? She just makes me. Patience and consistency...you'll both get there. I keep telling myself that anyway