Wow, you have an awesome relationship with your husband. You obviously care about him so much that you are concerned for how he is doing. I can see that love in how much guilt you are putting on yourself about your relationship with him, but I really don't think that helps! And he seems really supportive and caring.
Work appears to be a stressor, so you may be able to access support through their Employee Assistance Program (ask your HR department if you don't know how to access this, but Coles definitely have this program running!).
I would also urge you to see your GP and discuss what is happening for you, seeking a referral to a psychologist, as this is not the sort of thing you are going to be able to handle on your own. You do need to seek professional help, as the suicidal thoughts, the wanting to sleep in a hotel- these all point to quite a significant level of depression.
When you meet your psychologist, make sure that you can relate to them easily. If you can't, tell them so and seek out another psychologist (or ask for a referral) that you do relate to. The therapeutic relationship between you and your psychologist will be very important.
You can find psychologists at www.psychology.org.au/find-a-psychologist or, if you like, I would be happy to help. My details can be found on my profile page.
Keep us posted about how things go for you.