Advice please

Hi, 

I have been with my partner 5years and was aware he had a historic gambling addiction and sought support via GA. He said he does bet on football and odd horse bet still but it wasn’t an issue anymore. We have since had a young child and I have found out that he has been gambling a lot of money I checked the history of one app and felt sick. Anyway I have sat down to speak with him multiple times and he just keeps lying to me about the apps he uses, I’ve now got his banking app on my phone he said he doesn’t want me looking at the past on there which I get but also I need to see. So I have checked over the last 6months and he’s got accounts everywhere so it seems. I’ve asked him multiple times to be honest I’m not here to judge him I’m here to support. I have since seen he has gamble thousands of pounds over the last 6 months. I don’t even know where or how he’s been able to get hold of this money. Anyway I have spoken to him about seeking support from a professional he avoids it, firstly he wants me to support him (but I’ve enabled him as it currently stands and I don’t have the emotional capacity to do so) he also said he gambles because he’s bored etc. secondly I’m blind to his behaviour and little things that he might do so unable to hold him accountable. 

my question is….. anyone has a history of gambling how do I approach him in regards to seeking support? Because I feel it’s a hard boundary for me, if it’s not something he’s going to do then I feel we cannot be together. I’m driving myself insane with not being able to trust him. Sorry if this comes across as selfish as I know I’m not thinking of him, I don’t understand it. I’ve never been in this situation before and I feel a little helpless. 
please be as honest as possible. 
thank you for reading sorry if it doesn’t make sense.