Bleach/box dye gone wrong :(

Hi everyone, this is my first post on this forum so I'm really not sure if this is the correct place to post it but it is about hair dye and bleach so I hope it's ok, so I have a disaster right now and I really could use some help il explain...
So in 2013 in dyed my hair platinum with feria blonde dye and it was totally fine worked and everything, I didn't want to keep on top of this so when the roots came in (dark ashy dirty blonde type colour) I dyed my hair light Demi-permanent brown and by the time that washed away the banding wasn't bad so I was able to keep my hair and let the natural grow out, I dyed Demi-permanently dark brown in February 2015 and it had faded back to a very light brown / blonde colour with about 2 inch of ashy roots so I decided to opt for platinum again (no idea why honestly wish I hadn't I'm regretting it so much) so anyway the roots have went bright and yellowish, the rest is patchy with dark bird and I really really hate it so much it makes me cry I have no desire to keep this colour whatsoever so I'm just wondering what would be s good idea to help the patchiness and then let the natural grow in and basically never dye it again! I have thought of a few ideas but I can't go to a salon as I'm low on money so I thought either demi permanent light brown or permanent sandy blonde by olia (I can't use dyes with ammonia) will this damage my hair in a bad way?? Or even will it help? Will it go green? Etc? I just really need help on what to do to get my hair back to a colour I like also when the Demi-permanent dye washes out will the blonde be as bright and yellow?

Any help is appreciated, i really don't know what to do about this without causing frat damage to my hair and I eventually would love to grow my hair long

The pictures ive added is my hair before the box dye (darker) and then after and also the both dyes I was choosing between