Make a list of all the stuff you do that you feel is beyond the role you are being paid for. Next to each item on that list write down how you think it helps the company.

In the meeting, use those points to illustrate why you think it would be a win-win for both parties if you got your raise and promotion.

Have a clear idea of what you are asking for in terms of money before you go into negotiation.

Negotiate based on facts and goals instead of needs and "time spent" or similar.