As encouragement, I have a son-in-law who cycles 13 miles from Hanwell to Waterloo and back every day....
I'm a cycling instructor based in Finsbury Park and you are welcome to contact me for advice. I can help you with gaining confidence while cycling in traffic and find some good routes to work. I've been cycling in London for over 30 years and have worked both as bicycle courier and van driver in the past so I have a vast range of experience and still love cycling.
If you live, work or study in Haringey then you are still entitled to 2 x 2 hour lessons for free with a cycling instructor.
Click on the link below and follow the instructions. You can select which instructor you wish to book from a list and they will contact you to arrange a suitable time and place to meet (this is the same link that Alison P provided).