How can I manage smartphone addiction affecting work, sleep and seizures?

[Pugfan]

I have been warned I am going to lose my job due to my smartphone addiction. I constantly get distracted by my works WhatsApp group. I go on to check the messages & end up checking emails for a while. I go online to research work related tasks & end up watching how to videos on YouTube for hours. I stay up late watching videos & researching information. I've had two seizures since Xmas which no cause has been found. On the days I had seizures, I hadn't been to bed the previous night as was on my phone.
I had a disciplinary a few weeks ago & boss is concerned that I'm constantly on my phone & very tired. I said I feel addicted. We agreed I would go to my GP for help whilst I was on annual leave last week.
My GP wasn't supportive & said there was no treatment for this addiction that he could refer to. He advised me to turn my phone off at work but I don't feel I can do that as my team work in different locations and we use WhatsApp to communicate. He referred me to the Mental Health Crisis Team who were unable to help as I wasn't deemed to be an urgent risk to myself or others. They did provide numbers for cleaners as my house is in a bit of a mess as I'd rather watch videos than clean & for Citizens Advice for benefits advice when I lose my job.
I think I've tried every screen time blocker out there including Opal, Screen Zen & Brick but I usually uninstall them or smash up my phone with frustration & buy a new one. I've also tried Internet Addicts Anonymous but find it impossible to turn my phone off after meetings.
Has anyone been able to live with this addiction & function? Does anyone have advice as how to search for a job without getting distracted? I'm worried I'll get a UC sanction as I won't be able to search & apply for jobs.

Do you have a partner or another adult living at home? If you do get a locked box and give the phone to them to put in the locked box, they are not to give you the key until the agreed time, give yourself half an hour after work to doom scroll then into the box for an hour. Gradually increase the time to wean yourself off it. Set a time at night that’s a reasonable bed time and your phone goes in the box and doesn’t come out until the morning. Consider a smart watch for work? You can still see messages make calls etc but not suitable for aimless scrolling. Do you read? Try and replace nighttime scrolling with reading a book or magazine. Try and get into a to show to watch in the evening. Basically anything to get you off your phone and keep you distracted.