There are several techniques you can use to focus on what matters more. Getting rid of high-speed internet is not a solution in a digital world. When a person gets out of one pattern he will get stuck in another. The real issue is a lifestyle change that you need. Take a habit coaching and pattern recognition session with a life coach. Understanding yourself is a better solution in long run.

Dear concerned please do visit a neurologist & clinical psychologist to help you come out this problem as soon as possible. You can connect to me on practo consult.

Appreciate your willingness to seek a professional support.. I am sure you would have tried many things.. Probably, 1. Changing you  net connection to a normal prepaid account might prick you for having to pay and renew it every now and then.. 2. Change you mobile to the old model, where you do not need an Internet connection.. 3. Maybe because of the above , you maybe able to focus more on work during your office hours otherwise, you may need to face other consequences.. 4. Practice to be around people.. Interacting with them, might be a great source of diversion..