Hair help

Hi everyone could use some advice!
My natural hair colour is medium brown.
I used to dye my hair red when I was in younger and then grew it out... Well cut it out I guess as I went really short style wise. I then had highlights when my hair grew longer and retained my natural colour again.

I then grew out and cut out again the highlights and have since then let it grow naturally.
I went to have it cut and they hairdresser recommended I used a hair stripper or colour b4 as my hair was all sorts of different colours. I did, it went bright ginger but I stuck a semi permanent med brown on it and let it grow out, that was 2 years ago.
Since then, I've just been putting medium brown 12 week wash out dyes on it every 4-6 months

Now I'm back to square one as my hair colour is back to natural until about 3/4 of the way down. The ends are a lot darker
I've found a good deal at a local salon to have it all re coloured, but I also have another box of colour b4....can I just put it on the ends and then use a semi perm? To make it all one colour.

Really unsure of what to do 🙁 are there any good options?
X