Aww - I'm sorry you are in such a difficult spot. I know it sucks. It is your life. Don't erase it. Don't wish it away. Cherish it, every minute, and know that it is all yours. Box up those 4 years and put them on a safe shelf and when you are ready you will open that box and look through it - and realize there are parts that were real and worthy.
FWIW I still have my ring. Someday I will remove the diamond and have it put in a different setting. When I have time to really get something meaningful.
I still have my dress too although I have no idea what to do with that. I don't even have daughters. Despite the fact that this ended sadly under an avalanche of broken dreams and broken promises, that dress symbolizes a pure and honest day of happiness for me. I will probably end up donating it - or maybe cutting it up to make something else with, but for now it just stays in its box at the back of the closet.