Boost problems again

After finally sorting my boost problems last time, with a combination of the following new bits:

New silicon intake pipe to throttle body silicon hose
Intercooler (old one had hole in)
New WGFV
New plugs
New recirc valve
New 034 Motorsport loom and 1.8T coils

It ran perfect for a short while, showing ~12psi on the gauge.
It is now cutting the boost again

If you warm the car up, and give it full boost, it will show full boost, but doesnt feel "right".
Lift off and try again and it is noticably holding back (feels like fast pulsing on and off boost) but still shows full boost.
Lift off and try again, it then gets to about 5psi and the ecu cuts boost suddenly.
Then everytime of trying after that, it instantly cuts as soon as you try to give it any boost.
If you press the accelerator lightly, you can just about get to 5psi or so, but its still holding back.
It will then continue to cut it instantly, until you park it up, then start again from cold and its the same thing all over again.
So part of me is thinking the heat is killing the coils?

Before I got the 1.8T coils I read varying opinions of some saying they were fine, and others saying they were not up to it.
I am now guessing that they are were, but have already been killed off?

I can see my only option is to buy some brand new OE coils, and boots, which I cant afford at the moment

I am desperate to get it sorted, as its not been running correctly for the majority of the time that Ive owned it so far.
I am now getting to the point where I will sell it as soon as its fixed again, but part of me can see the light at the end of the tunnel and know I will love it once its homefried, but I just cant seem to get to that point!

If anyone is able to come and help, or me come to you and try some known to be good coils to see if they will sort it, I am more than happy to pay for your troubles as I just want to get it sorted