My suggestion would be to focus on just one layout. It sounds like you are having trouble mentally switching between them.  Focus on one and you should regain the ability to type.

Also do you really mean you can only type 5wpm with colemak after a month and a half? If that's the case I might suggest going back to qwerty.  You don't want to spend several more months trying to regain a functional speed.

That is quite normal, it happened to me during switching process and I think it happens to everyone too.

That's how I call "jumping off the layout cliff". Since you keep both layouts during switching, and that worsen both Qwerty and Colemak speed. Eventually you will reach the critical situation when you can't type well in both layouts.

You have to switch to Colemak fully to further improvise and let the new Colemak muscle memory wholly imprinted in your brain. Surely it will be difficult at first and you will cling to glorious Qwerty days.

You cannot cross river with two feet on two different boats. That day will come when you cannot type well in both layouts and your fingers get confused, refuse to improve. Be brave to go all the way and switch to Colemak full time to solidify your muscle memory strength.

This is where you need to read our forum experience to muster your confidence to pass that critical point since so many people have overcome that and somehow still stayed alive. All of us need that little encouragement when it is needed most and will be grateful later when Colemak fluency becomes a reality.

I went through the same stage as you approaching 70wpm on QWERTY by I have nothing else to do so decided to stick it out with Colemak cold turkey, no Tarmak. That was 7 months ago and my Colemak speed is now starting to surpass that.

You will go through a stage where you think to yourself 'oh shit what have I done learning Colemak now I'm completely screwed!' but as Tony_VN says you can't keep your feet in both boats and you have to decide to let go of QWERTY all together and carry on with your own mission. You can always go back to two finger typing on other keyboards.

My only niggle with Colemak are certain finger twister combinations like 'you' and 'ion' on those outside fingers which take their toll as you get tired.

I think all Colemak and Qwerty skills are still there, panic and confusion just do their work quite well. If the topic starter continue to practise Colemak regularly the speed will come back.

At the end of three weeks my Colemak speed was 20-25wpm already, so after a month his Colemak speed can't be lower than 15-20wpm. I think he need to be persistent and go straight to Colemak abyss, just like us all.

By the way, I think Colemak is not for everyone. You have to be strong enough to be different from all Qwerty-centric world. Conformers need not apply.

Maybe his hands are covered with duct tape and zip ties or something?