Don't do it!! Life is too short to be a slave to the commuter train.
I have all but given up on my career prospects. I am stuck in a job that was promising when I started it some 12 year ago, but now is mundane and I am stuck in a rut. However I am part time and do 16 hours per week spread over 2 days. On those 2 days I work from 8am till 5pm and my kids go to after school club. They are tired and ratty when they get in (as I am), and after sorting them out with dinner, homework, bath etc. I then get to the yard at about 8pm. I hardly get to spend anytime with the kids, I rush through riding my horse and then say 2 words to my husband when I get home before collapsing into bed. I am glad I only have to do this 2 days per week, if I had to do it everyday I wouldn't be able to cope.