Help with roots please? (Red matching conundrum)

So for 3 years now I've been dying my hair the same shade of red (Ion permanent dark red blonde), but I always do my roots then the rest of my hair. I use 20 developer, so over time this has done a lot of damage to my hair. My hair was down to my waist and I just had to get 5 inches cut off yesterday because of all the damage, it was unmanageable 🙁

The issue is that when I originally dye it, it's really red, then fades out into a more natural looking red- thus why I've felt like I had no choice but to dye all of my hair every time instead of just the roots. But I really don't want to do that anymore, because of the damage it's causing.
So my question is.. how do I go about dying my roots the same shade as the rest of my hair is now (now that it's faded out)? I am worthless at color matching, and all the salons have said that they would do the same thing I do at home (roots then ends, that they can't do just roots). Is there any way to do this without it turning out a mismatched disaster? If I dyed it then shampoo'ed it with clarifying or non color safe shampoo would that fade it out to where it needs to be? So lost :/

I had also considered dying my roots with my normal dye, then doing my whole head in semi (like adore). But am also unsure how to go about that. Since as I said the dye when it first comes out is pretty bright and red, and mine is more of a natural (though a bit darker) looking red. Also becuase I tried a semi last year and it didn't stick to my roots but maybe for a week (which I found out later you have to process it first for it to stick). So obviously I have to process it somehow to get it to stick, but I'm afraid if I just bleached the roots, it would turn out really weird looking since the rest of my hair is red and my natural color is a light brown.

My thought on this was maybe doing the roots with my usual dye (with dirty hair), washing it and the rest of my hair with clarifying shampoo (since i've been told to use that before semis), letting it dry, then doing the semi dye. But I have NO idea if this is even the right train of thought to be following here..

So what do you guys think? Any advice or tips? Thanks 🙂