Is there ANYTHING I can do to help stop my fiancé from being deported?

Question did not provide sufficient information. Reason for deportation, how long in US, method of last entry, etc.

Hiring an experienced immigration lawyer ASAP is what I'd suggest, especially if your boyfriend already has a deportation order. An emergency stay of deportation must be filed with the IJ who ordered his deportation. A quick review of his EOIR file will provide the reasons for his removal order, and this should offer some pointers as to the legal arguments for a successful MTR .Actionable information from DHS / ICE cannot come fast enough and so, your boyfriend can assist in his own case by being forthcoming to the lawyer about every fact of his case.. From experience, your boyfriend will have some ideas about all of this and so, he must share this with the lawyer including his immigration and possibly criminal history, if any. So, please consult with a lawyer as soon as possible.

Your question requires an attorney consultation. It is not a simple question that can be answered on this type of forum. There are many factors that would need to be considered and evaluated.

There are options available to prevent deportation/removal. However more information is required to see if he qualifies. I recommend you consult with an Immigration Attorney.