I BELIEVE THIS IS THE ANSWER for any future ppl who have this problem.
This answer was never really solved here i think? it got me thinking i had 85 gb of free space on my SSD when i started this project now i have 0… WTF? i save all my renders to my hard drive not my ssd and still the ssd is getting filled up! GRR!
welp be prepared to feel stupid cuz i sure did when i figured it out.
in sony vegas : file – properties – 3 lines from the bottom on the video tab… PRERENDERED FILE FOLDER <—- needs to not be on ur C: drive lol every time you have made a temp file or a pre rendered file, (aka hit SHIFT+B or SHIFT+M) which is ALOT if you have a below average computer for hd editing like me, it saves all of these small renders into a folder under your appdata which unless you have it visible u will never see.
they are so small in fact that it took me 1272 pre renders in 7 months to fill up 85gb of memory the largest file was just over 1MB lol
https://puu.sh/sxtWb/c720c722ac.png
the direct extension is
C:\Users\USERNAME\AppData\Local\Sony\Vegas Pro\13.0
i dont have any suggestions on what to delete or what not to delete but i would say just sort by date and remove anything older then a week for starters then figure it out from there.
hope this helped someone out there