Is Plan B worth it?

Kristina • Getting married on 6/20/16
My fiancé and I are doing our best to avoid pregnancy at this point in our life. Mostly because we don't have the money for it. Anyway, the only BC thing that we use is condoms because I can't take the pill because it messes with my emotions too much and I become suicidal. So I was just wondering if Plan B would be worth it since I'm prone to side effects? I often get the uncommon side effects no matter what medication I take.