What over the counter hair color to use?

My naturally dark brown hair is now medium copper on one side and light copper on the other when I asked for light brown, thanks to the beauty school. It was bleached, colored super fried and too late for color remover. One side is a lot darker also because of permanent low lights there and not much on the other side. My scalp is bright gold brassy which does not match the copper thanks to the professional I saw after the beauty school (who also did the permanent low lights mostly on ONE side and the 40 volume highlites that failed but damaged....) Brassy hair remained after I saw her. I want to cover it all up but *not* go as dark as my natural. No more bleach, no more high volume, no more permanent color for me. Want as gentle as possible. I am not too concerned with my roots not matching perfectly because already I am walking around with brassy blonde and the dark brown roots. It would be less noticeable when the hair is darker overall even if roots are darker. My hair is multi colored which makes it hard. I guess I need a demi as a semi does not last long and maybe won't be pigmented enough to cover it up I hear? I am willing to keep some red for the sake of not going too dark, if that is waht it means. Bought some Loreal Gem in ash blonde as I was told to go lighter because colors run dark. Yet was also told that dk blonde won't do enough to cover it up as it does not have as much pigment. Aggg! They also had light ash brown. I was told that any ash can make processed hair green! Got it at Sallys, 9% peroxide no ammonia, the others did not say the peroxide % so I decided against them. Wondering if I should use that or Loreal Colorspa in light ash brown? But those store bought ones do not say the level of developer. And I do not know how high I should go to get the job done but minimize damage. I also wonder how often I will have to redo it. I am aiming for medium chocolaty deep brown and I do understand my hair will be different colors as I am starting off with different colors. I want to do myself as I have had too many problems with others doing it that are suppose to know more. I even went to a consult recently where she did test strands right in FRONT! It was not hidden at all and ended up super dark. And on top of that she would not tell me what she charges. Any suggestions? SO confused. THANKS!

 

Here are my pics before coloring, after beauty school and after the professional (the dark is before color, the brassy is after beauty school, the still orange brassy but now with brassy gold scalp and low lights on ONE side is after professional) :