Hi @Mumo4,
A warm welcome to the SANE Forums 
It must be so hard going through shopping and gambling issues and keeping this a secret from your partner. I can definitely appreciate that you cant bring yourself to tell your partner about the debt and this must be incredibly stressful. if he is enquiring with the bank about refinancing that is a possibility that he will find out. It may be a matter of you thinking about how you would like him to find out about the debt.
@pip has a good suggestion here about contacting Gamblers Help. This may be a good place to have an initial discussion about what is going on and the possibility of your partner learning about the debt. If you are interested in this, you can look up the number for gamblers help using a search engine, sorry I cant provide the number here for you but the number differs depending on which state your living in.
What sorts of support do yo have in place at the moment @Mumo4? Support and self-care are so important during times of stress.
Talk to you soon.
Take care 