Forge messes up my client [1.8.9]

[TG_MC]

So I use forge to play PvP, and I tried to run forge about two days ago and it doesn't work properly. What happens is the players are glitched an have got their arms waving everywhere. If I try and move forward (pressing 'W' only) I move diagonally left. The movement is distorted for every other key as well. Also, no matter which direction I turn it goes the same way it did before. Also, the screen is glitchy. I tried to attach a video (idk if it worked). If anyone knows what is up or how to fix it I would appreciate the help. Also please don't just say "Don't use ancient versions" because unless there is a mod that makes 1.12 exactly like 1.8 then I'm sticking with 1.8. Like I said I'd appreciate any help you can give.

Bug Report.mp4.wlmp

[TG_MC]

20 hours ago, diesieben07 said:

You attached a windows movie maker project file...

 

Yeah, I realized that a while ago (oops). Also, it doesn't happen with my 1.12 forge idk why (obviously). Again, I appreciate any help.

[TG_MC]

Are you kidding me? That doesn't help at all. I need to stay using 1.8 and I am asking for a solution to my problem, and all you do is tell me the thing I told you not to. Update your client. Surely you actually know how to fix it rather than saying update.