Confirmed lash egg! Need help treating

[Saltymiso]

So my almost 6 year old chicken (her name is flower//I didn’t name her my 6yr old cousin did lol) laid a weird egg over a month ago but I wasn’t able to confirm that it was a lash egg cause it was more like an abnormal egg but I had no idea which of my 11 chickens had laid it either. I’ve been keeping a close eye on them and I’ve noticed that flower started acting slower than usual and hasn’t layed any eggs since she stopped laying in winter.
I also saw she has a dirty vent with poop fragments on the feathers around it and also kinda missing some below her vent.
Well today I found a lash egg cut it open solid all the way through
I’m not posting a picture of it cause I’m so sure it’s lash that I don't think a picture is necessary
Just a literal chicken nugget
Anyway I was looking around at other threads for help treating and found this link https://jedds.com/products/enrofloxacin-10
And my mom helped calling some feed stores to see if they had any treatment
Unfortunately we do not have a vet and do not have the extra money to pay a visit due to a tough money situation.
I hope it’s not too late to treat her and any advice is greatly appreciated!!!!

 

[Eggcessive]

Usually, by the time you see a lash egg from a hen, it may be too late for antibiotics such enrofloxacin or amoxicillin to help much. But it doesn’t hurt to try. Salpingitis/inflammation of the oviduct is the cause of lash eggs, and hens may have it for sometime before symptoms show. There is no cure, and it will eventually be fatal. Here is one of manny good articles to read about salpingitis and lash eggs:
https://the-chicken-chick.com/causes-of-lash-eggs-salpingitis-by/