justcurious - if you are still around a few more thoughts below.

Careers in finance is very competitive - more so for graduates. You have to be awfully bright to convince your prospect employers that the only way they can hire you is if the green card sponsorship is part of the offer. If you are worth the hire they will bend over backwards to have their legal team draw up documents. This is the ONLY way for you to start your career in finance AND be able to reside in the US, given you have no other means for path to residency.

If the above sounds farfetched why not stick with your accounting job and apply to positions like  tax or F/X accounting - positions that are very specialized and not many people find these too exciting. But for you though it may earn you a green card. And these experiences will not be wasted if you move onto finance at a later point.

If green card is not so important to you there are far too many opportunities outside of the US - so by all means weigh your options carefully.