Problems with Decluttering my Wardrobe

A few weeks ago I decided to declutter my wardrobe. By wardrobe I mean my actual wardrobe I share with the bf as well as the closet we have in the living room which contains a little bit of everything. My conclusion is; I have a lot of clothes and I don't use all of them regularly. What I decided to do, as I'm not ready to let go of them all just yet, is that I boxed almost everything up. I simply took some boxes we still had in the apartment after moving in ages ago, and just threw the clothes in there. The goal is to donate them to a local charity shop if they remain unused, but that might be quite difficult for me.
The reason I'm not ready to let go of all these pieces has a simple explanation; I might actually need them. The thing is, I like playing dress up. I go to my fair share of themed university parties and for these parties I need a fair share of obscure clothing. My closet includes everything from a DIY IKEA dress to devil horns. Since I go to these parties bimonthly the clothes do come to use.
If I would get rid of everything that isn't monochrome or somewhat sterile I wouldn't be able to come up with funny outfits for these events. You might think "But why don't you just rent an outfit when you need it? Then you'd get rid of all those extra clothes!". I have two things to say to that.

1.  I am a last minute type of gal. I usually come up with what I'm actually going to be by looking at what I have to work with and then get creative. That is usually only a few hours before the event.
2.  I'm a poor student and that would be an extra expense which I can't afford. I'd rather just have a box full of clothes for free that I can work with, even if that means clutter in my closet.

But, with all that said. There will be a deadline for these clothes. The absolute due date is the day I graduate with a master's degree and no longer belong at any university parties, but hopefully I'll be able to get rid of some of these clothes before that. They have at least gotten their own box in the closet now and won't take up any extra space by being among my everyday outfits.

If my 12 readers from yesterday have any ideas or advice on this subject, please leave a comment below. I need all the help I can get.