Okay, let me just put this in perspective for you. Adding a PCI-e slot on a laptop is a VERY difficult task. You need to know a lot about soldering and power supplies. Moreover, replacing a GPU on a laptop is 20 times harder then replacing it on a regular 'ol tower. What I'm trying to say is that you can save a lot of time and frustration if you save your money to buy a a gaming-laptop (or if you're feeling crazy; build your own desktop), from the looks of it you think that you need a multi-thousand dollar gaming-laptop to have an enjoyable experience when in reality that's VERY far from the truth.
Here are some budget gaming-laptops I found just by lightly searching Newegg that are significantly better than your current laptop:
Acer...