Please help me fix my chaotic dyed hair (SPLAT, HiColor, Color Oops..) before graduation!

Hi everyone. I’ve never asked for help on Reddit before, but I’m genuinely desperate and need some guidance from people who understand hair better than I do.

I used to have thick, long, dark brown virgin hair. Then I dyed it with L’Oréal HiColor in red and magenta using 40 developer (I didn’t know better at the time). I did this multiple times until it got super bright red.

After a while, I got bored and used SPLAT Midnight Tanzanite to go purple (yes, I know SPLAT is bad, but I didn’t back then). The color actually came out really pretty, a magenta purple, and I loved it. But it faded after a few weeks back to red.

Then I dyed it blue-black with box dye, just to have something low maintenance. I kept that for about 3 months, until I got impulsive and used Color Oops to remove it. I didn’t use enough though, so it left me with some patchy brownish-orange tones.

A month later, I got bored again and dyed my roots with HiColor Honey Blonde, then added Better Natured permanent purple dye on top. That faded in a week, and now my hair is a complete mix of colors roots showing, red, orange, purple patches, and the outside is mostly brassy light brown/orange.

It’s been around 3 months since all that, and my hair has grown a little. Now I need to fix it ASAP because I have university graduation photos coming up (I graduate this coming year, yay!), and I really wanted to do full blonde highlights so I could just use color-depositing conditioner from now on for vibrant colors without so much damage.

I went to a local hairdresser and she told me that because my hair is too brassy and orange, she can’t do blonde highlights yet, and that I should dye it the same color as my roots first (dark brown). I’m confused on why that would be necessary. Is she saying I need to even everything out before bleaching? Should I actually do that?

I’m aware my hair will get more damaged from this, but I really want to enjoy fun, colorful hair while I’m still young, before I have to look more "professional" later in life. I just want to go about this the right way now.

Please don’t be mean, I’ve made a lot of mistakes but I was just broke, bored, and trying to express myself. I’m trying to learn and take better care of my hair now. If anyone has advice on what to do from here, whether I should dye it brown first or do something else, please help me.

Thank you so much in advance 💜