red bleeding through

almost a year ago i box dyed my hair a blood red, had it for a few months and tried to go to a natural colour. i've tried dark browns, ash blonde, blonde, medium brown even a colour remover, it works for a couple weeks then the red just bleeds right through and im left with a super brassy colour. i hate going to the salon + im a student so im broke.
what can i do to fix this brassy bleed through? im willing to go to sallys and mix my own dyes im just wondering if it will even make a difference?

i tried to find pictures online similar to my colour now and my natural colour. i'd like to get it as close as possible so i can just stop dying my hair besides adding blonde in the summer months.

here's something similar to how my hair currently is/ always ends up being :


and here is a close representation of my natural colour:


note: im just looking to get the base colour back to normal so ignore the lighter blonde she has in the front.