I'm sorry to hear about your hen.
Just a few things to ask - what type of food/treats do you feed?
How heavy is she - does it seem that she has a fatty rear end?
Unfortunately, laying issues are common in hens - sex links are high production birds designed to churn out the eggs, so I feel they may be even more prone to have these problems.
Being constipated, egg bound and prolapsing is a compound problem. The first thing to do is evaluate your food and treats.
Is she drinking well? Dehydration plays a huge roll in egg binding along with being too heavy (excess fat in the abdomen-restricts the smooth passage of the egg).
Make sure she is drinking, that her main source of food is a balanced poultry feed and limit treats to no more than 5% of her daily intake. Scratch/corn is low in nutrients and packs on the pounds, so make treats something a bit more nutritional (imho) greens (kale), cabbage, broccoli or a little fruit would be better as a daily treat.
Add poultry vitamins to her water once a week and make oyster shell available free choice - calcium helps not only with making hard shells, but also helps retain a prolapse. She may benefit from extra calcium for no more than 3days - you can use a crushed TUMS or 1/2tablet of calcium supplement like Caltrate.
For constipation you can give molasses in the water (use the molasses only 1 time to get things moving - it causes very loose stools) or direct dose her with mineral oil or give her a little coconut oil (my chicken will gobble pieces of coconut oil). As with anything moderation is key - don't overload her, give a little and see if that helps with constipation. Constipation could be due to fat or inflammation of the oviduct (or in your case a stuck egg) constricting the function of the intestines.
It always seems to be a favorite that has problems. To permanently stop egg laying, you will need to seek vet care about Suprelorin Implants - that may be an option for you. https://poultrykeeper.com/reproductive-system-problems/suprelorin-implant-for-chickens/
The only other thing I know to do would be to limit the amount of light to around less than 8hrs a day - that would mean caging her and keeping her in the dark. Short term, this may help stop production and allow her to heal, but long term, you would have to determine if that is quality of life for her.
I love her I came home after hiring a pet sitter to care for my five-month-old silkie hen and her vent looks very strange, swollen, and stuff draining from it, is this Gleek?
How long has she been like this?She’s only 2-3 lbs, doesn’t eat many treats, mostly purina crumbles and I keep oyster shells on hand. She has not yet Lang. She seems to be straining when she’s pooping and only a little bit comes out.