Hello to all who managed to maintain more than one keyboard layout. I need your advice on my problem.

I've been using Qwerty for 27 years & my latest speed was 130+wpm on monkeytype before I converted to Colemak dh.

My Colemak journey started 3 months ago with the initial goal of preserving my qwerty too. In my first month I trained Colemak dh on an ortholinear keyboard but I made sure to keep using Qwerty on my laptop keyboard so not to lose it. I even use my other thumb for spacebar on Colemak to make sure the layouts are handled differently inside my memory.

The approach didn't turn out well. Typing on both layouts made my Colemak progress extremely slow that I was struggling to reach the 25wpm barrier on my 1st month. For that reason I went cold turkey Colemak on the 2nd month and from there I started to see faster progress. One & 1/2 months more and my Colemak speed reached 80wpm. I enjoyed colemakDH particularly the rolls but there is a problem: My qwerty memory was lost!

It's hard to believe but it's really lost and I'm not prepared for that. I have a high respect on Colemak but my PC usage ways & requirements made me realize that losing qwerty is my big blunder. I was relying on some claims that qwerty will be relearned after few hours of practice but it didn't happen to me. Not even close. This is my 3rd day of qwerty retrieval and I'm still around the 20wpm range which is depressing thinking that just 2 1/2 months of Colemak wasted my 27 years of qwerty experience. I know that I will get there but I wonder why it's too slow in my case. My current goal is to relearn Qwerty but keep my new Colemak as well that's why I practice them both now. I need your help on the right training approach with the minimal damage effect on both layouts when I use both. Is it better to train them in separate sessions with long rest in between? Or is alternating them in one training session beneficial for retention or harmful?

Thanks for the advice.