What haircut should I get?

Hi, guys I am new to this forum and I need some help. I haven't pulled my hair in 54 days, which is great!

I'm going on vacation in the beginning of May and I really don't want to have to wear a wig the whole time. It's been 4 years since I have worn my own natural hair out and about without a hat or extensions or a wig on so I am very nervous to take this next step.

My hair right now is a crazy mess, it's long in some bits and a mixture of thick and thin everywhere so I majorly need a haircut (something I also haven't gotten in years) I just need help figuring out what I can do and what you guys think will work and also hide a little bit of my thinner areas.

My thoughts right now are to get and under cut and just have all of the hair on top flipped to the side that is thinner to cover it up a little. Also MAYBE if the sides of my head grow out a little bit in the next 30 days before I get my hair cut then maybe I could have a really really short pixie cut. What do you guys think? Also please link pictures of examples if you can! :)

Thank you so much for all the help!

Here's a picture of my hair now: http://imgur.com/gZ26o9G