Drink and drugs.
I do these things, it's true (shock news I know), but I also run a £1.5 million turnover business, and I've never once missed, been late or turned up for my visits in anything other than 100% clear-headed, totally dedicated sober form and never would I. My visits to my child are the high point of my week (and life) and I will never jeopardise them. I am NOT a liability and my child is as safe with me as with her mother.

She knows this, she's just being a cunt.
( Monty Boyce, My cheese game is strong, Wed 15 Sep 2010, 9:11, 2 replies, latest was 15 years ago)

Tell you you have cleaned up...
...and don't go near any 'mutual' friends when you are partaking.

Or just stop the drugs and drink.

...

...

HAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHAHA!
(
(Tugnut Ex of this parish, Wed 15 Sep 2010, 9:28, Reply)

You may not be a liability (and I am somewhat late to the party here)...
But I doubt the courts would ever see it that way. I imagine that the argument would be 'just because nothing has happened so far, it doesn't mean that nothing will happen at a future point'. Whilst I'm not going to condemn the choices you make recreationally, I'm afraid that as long as drugs are part of your life then you're fucked, access wise, because some of the activity you are involved in is, let's face it, illegal, and considered socially and morally unacceptable.

If, as you say, the highlight of your week (and life) is being with your child, then to me it's an easy decision to make; no contest. If you were in a situation where your ex died suddenly, and custody of your daughter was denied to you because of your social activities, you'd be pretty pissed off about it I'd wager.

That may have come across as a bit Daily Mail but it isn't meant to be
( Davros' Granddad a voice of calm reason in a world of spastics., Wed 15 Sep 2010, 13:24, Reply)

Also
Doesn't your ex partake in the marching powder as well?
( Davros' Granddad a voice of calm reason in a world of spastics., Wed 15 Sep 2010, 13:46, Reply)