[Help] Hosting And Playing On Same Computer

[kasene]

Hi this is my first post

me and my friends made a little private server that we like to fool around on but i host the server on my computer witch is the same computer i play the client on. the client has lots of problems including lag and the screen gets all glitched up when i try to move anywhere.

it is still playable but quite anoyying is there somthing i should be doing or not doing

plz help