Hey guys, I'm kinda new to this

I jailbroke my iphone and had cydia installed recently after having my iphone for like a year. I jailbroke it before as well but I never updated the software till last week.

Today I tried to download something on cydia for the first time,

I was trying to download a springboard theme and I wasn't sure if I needed another program to get the themes to run like before so I decided to try it.

After the installation, my screen goes black with the apple logo and doesn't boot up for 2 minutes.

I tried to start cydia up and it will automatically close on me every time I try to run up cydia.

Any way to fix this?

Thanks