Help Please - My partner's addiction sucks

Hi, 

I am after a bit of advice as I don't know what to do anymore, I feel the consequences of my partner's gambling can't get better. This is going to be a long post so apologies in advance - I hope that's ok. I don't really have anyone to talk to about this as my family lives abroad and adore my partner and I don't want to worry them. 

A little bit of background, I found out because my partner owes a large amount of money to people which I know and it got out around 2 years ago. He stopped gambling around a year ago with a few relapses (last one about 7 weeks ago). He also owes me a substantial amount plus he took out a few loans & CC in my name (some without my permission).

I pay all the bills, his debts in my name plus supporting my son. My salary is not massive as I have to work less hours since September due to my health (cancer treatment) so we live from paycheck to paycheck. My partner's job is paid quite well and he works hard. But the monthly repayments of his debts take basically all of that.

The problem is, that every single month for the last 7 months, he asked me multiple times a month for more money as he has to pay this and that, otherwise he would be in serious trouble. I always say no but he talks me into it and uses the 'we are partners' card or 'this time will be different' etc. Well.. He either didnt send me the money back at all or he did but late and I missed my bills. I also had to change my passwords on my phone as he took my WHOLE salary twice as he owed money to some dodgy people.

I understand that this is an illness and he does horrible things out of desperation but I am so fed up now and I don't think I can take any more. But I am worried he would harm himself if I'd left him - he said that he is alive only because of me and my son and there is no other reason to live. 

He has counciling through his work because he suffers with mental health and has suicidal thoughts (that is due to the financial stress etc). I don't believe he told his therapist about the gambling. Although I don't know that for certain, my impression is they are trying to figure out how to get him in better mental space in general.

Since starting his therapy, he told me several times that I am a trigger for him if I nag about all of this. I hate that but can't help myself - I am super stressed how to pay bills on time and get food on a table. 

We cannot really talk about this together as it either ends in an argument or me crying and him being angry with me.

Any advice please? How can this get better? Just to add, I can't afford couple counselling. 

Thank you.