Title ownership on my property ?

It appears from what you stated that she is an equal owner of the real estate and to remove her from the deed would require that she voluntarily...

You do not get the protections afforded by attorney review as you would if you were represented by counsel.

It doesn’t seem like a very good way of handling it.

How do I put my name back on my deed?

Only the record owner (or his or her fiduciary) of the real estate can add your name to the deed.

I was planning on buying a lot in July of 2020 to build my home on, but my financing didn’t go through.

That would all depend on the language contained in your contract of sale.

Real estate must meet code. It doesn’t become legal by the mere passage of time.

I would check with the local building department before you close for an answer to this question.

Responding from a New York perspective, The fact that you presented appear to reek of negligence and breach of contract on a part of your home...

We had a contract on the purchase of a house in Essex county NY .

One would need to thoroughly digest the complete terms of the contract for those answers.

Any one given owner of real estate could force the sale of the real estate by bringing an action in partition which is, effectively, a forced sale...