As I said in group – I think what you are doing is brave and brilliant and gambling is a health problem so you shouldn’t feel the need to take unpaid leave. So what would I do?
First I would talk to GMA about it, as I (would guess,) not be the first with this dilemma and they may know what others have done about it.
Second – I would get a copy of my employer’s sickness policy to see if there is any regs / instructions on this already. I might even contact my union to get their take on the matter (for a friend and confidentially of course.)
Third – check with my GP whether they would issue a sick note to cover, given my situation (this would mean coming clean with them though)
Fourth – if it came to it, I might ask for a confidential meeting with someone in HR (possibly taking my union rep) to discuss taking the time out without disclosing to my immediate boss – but by then I may have decided to take unpaid leave anyway as an easier option … BUT
Would you have to give a reason to apply for unpaid leave anyway? I know when I wanted to go to Brazil to get married and had used all my paid leave up, I had to go to a meeting and declare my reason for wanting the unpaid leave before it was given – especially as a small part of it was in term time. They did give it – provided I showed them the wedding pics (presumably as that was proof that I wasn’t just having an extra holiday!)
Anyways – not an easy decision. I hope you come up with what is right for you. Wishing you well.