What do you mean normally? If you mean that the game gets lower frames in fights then in spawn, that's normal. If the game is doing less work, it will generate more frames.

well like, I usually get 150-200 normally in spawn, when I get to like, the mid of where fights are going on, it stays at a constant 100, then dips to about 70-80 and you can REALLY tell, so its kinda annoying.

Yeah, that's pretty normal. For example, I get around 500 fps in spawn, but closer to 100-150 in midfights. The drops to 80 from 100 are probably just from there being more action at that time (more spam, more players on screen, more of the map being rendered at once, etc.) Unless you have a computer which should be doing significantly better (i5+), it's probably just tf2 being unoptimized. You could try defragging tf2, steam://defrag/440 (put in browser address bar), but it probably won't help at all.

For me, randomly when I play tf2 my game will freeze and repeat the sound that was just played. So if I froze during a rocket jump, the same sound will be repeating for a short amount of time. I run dx9 aswell and I'm not sure how to fix this problem. A medic flashed me once when it happened, and when the freezing stopped it made a really loud sound and i got spooked :<. If there is any solution pls help

For hitches and stuttering defraying and ensuring your hard drive has adaquate free space is definitely something to try.

You might have to run on dx8 to get a better framerate. This game has terrible optimization.