Going from chocolate brown to ash/natural brown?

Hey there everyone! I'm new here, and I searched all over google to find help on my prob. but I'm on a dead end. So I decided that here (HairBoutique) is the perfect place to find someone with lots of experience who could give me a solution.

So my natural hair color is light brown, probably very dark blond. I think it's a cool tone, kinda ashy, but I'm not really sure but it definitely has yellow undertones and not red.

I decided to darken it last march or april (not rly sure) and I picked a dark chocolate brown hair dye cuz I wanter some red in it (got tired of the blonde). I loved the result rly and then I wanted it a little more red and dyed over it a dark auburn color. Then I dyed it dark natural brown but there were red (warm) undertones in my hair afterwards.

Now I DESPREATELY want my natural color back or at least I want a COOL (ASH/NATURAL) brown and NOT red/warm. I tried dying over with medium ash brown hair dye but I think there are still red/warm undertones.

I've only used Schwarzkopf's Palette hair colors. Could there be the problem why the ash dye is not working?

PLEASE, HELP me. I've gone to my hair dresser but she said she could do nothing, but I know there is a way cause all the celebs have their hair colored in different shades of brown and blond and so on, SO THERE MUST BE A WAY. :(

Should I use a different brand then? :?