Hi Freddie,
I’m sorry to read your post and to hear how badly your fiance’s situation is affecting you. It’s sad that you are feeling guilty as what you are dealing with is very hard.
I wonder if you are able to get any help for yourself as you are obviously exhausted by the caring and the worry. May be you could talk things through with your GP.
Also perhaps you would like to contact The Icarus Trust. We are a charity that offers support to people who are living with the impact of a loved one’s addiction. May be it would help you to talk with one of our experienced trained volunteers.
You can contact us on help@icarustrust.org or visit the website http://www.icarustrust.org
I hope that you can get some help for yourself.
All the best.