Relationship issues, I need help?

My fiancee wife to be and I have been arguing a lot lately. I've accused her of suspicious behavior and she's been getting angry at me over seriously ridiculous things. We're both losing our cool. Our anniversary is coming up this Saturday, and there's been so much tension between us, that I don't even know what to do. We're getting married in 3 months, and I don't know if it's the countdown that's creating the tension. What do I do?