nikon - What type of lens should I buy?

I'm fairly new to the photography and just recently have been looking to buy new lens. My boyfriend bought me a Nikon D3200 last Christmas and I just recently started using it more frequently. The bundle kit came with two kit lenses a 18-55mm lens and a 55-200mm lens. My sister-in-law also gave me a 55-300 lens to try and I LOVE it. I purchased my first 50mm prime lens this week and I'm slowly learning how to use it. I was wanting to purchase a few more lens to improve my photography skill but I have no idea where to begin. When I start looking at the different types of lenses it's a whole different language it seems and quite overwhelming. What type of lens should I purchase next ?