Embracing "Deep Work" for productivity

Do you have that feeling where you worked all day but at the end it feels like you got nothing done?  In past 7 years at Egnyte to reduce burnout every 6 months to an year I have to fight this constant productivity battle. I have accumulated several habits in the process to increase productivity, some of them are:-

1. Give yourself scheduled time: Allocate 3 hours for creative work, I had my calendar open whole day and I would get interviews and meeting scheduled randomly all over the day. When you are on a maker's schedule this is disastrous. I recently allocated 3 hours of calendar time and I reject meeting invite unless its absolutely urgent and I am contributing to it.
2. Walk in middle of the day: by the middle of the day brain feels tired and I cant code or focus so I started 30 min walk. I tried listening to podcast or listening music on the walk but that felt more work so I stopped doing it. I just walk and think on the current problem on hand.
3. 5 minute rule: If you can finish the task in 5 min then just do it rather than putting it on backlog.
4. Power nap: If I am feeling tired, there is no point in slogging I just set a timer and take a 15 min nap and it recharges me.
5. Email overload: This is a sucker, I have tried many iterations on it:-
1. Send an email from mailing list to waiting folder and only have mails directly address to you in the inbox
2. Send automated notifications like Jira/Confluence to trash
3. I get lot of email from marketers, I just delete them and also report them as spam so next time I am not even spending 5 sec deleting to trash.
4. There are many email I am copied where I cant contribute so instead of FOMO, if I see lot of people on the mail I don't even bother to read it. If its urgent someone will ping me.
5. If the email is too long then read it later at your own pace.
6. Phone: 
1. Turn off all sound notifications.
2. Don't install unnecessary apps on it.

Now these all I had tried but this December I had the same feeling that I am not  productive enough and then I read Deep Focus short book by Cal Newport that emphasizes Deep Work on 31st December and my recent productivity actions are:-

1. Social networks: I deleted my facebook and Quora accounts on Jan 1st. This has helped a lot because earlier I would check quora when mind was tired and it can sometimes consume 15-20 min in vain.
2. HipChat: If its urgent people will call you, I try to be offline as much as possible.
3. Twitter: I connected twitter account to Linkedin to post tweet to it and now I don’t check twitter. I was mainly using twitter as my reading log :).

Things I still need to work on:-

1. Email: This is again a time killer, I need to be disciplined to check it only 2 times a day, but I get so many emails a day it takes 2-3 hours every morning to curtail this beast and constant curating in the day to keepup at it.
2. LinkedIn : As Quora is deleted, I am having withdrawal symptoms, I check it 2-3 times to catch up on news. I need to reduce it to once a day.
3. Techcrunch: I check it daily once or twice(need to reduce it to once).
4. WhatsApp: I have turned off notifications and I check it once a day to catchup with family in India (not sure if I can kill it).