The Spirit Gives... self discipline??

I have been struggling with my diet and exercise plan.  It is simple enough to follow, I just lack self discipline.

Today I logged into YouVersion to read Colossians (I'm reading Colossians every day this month) and this was the verse of the day:

2 Timothy 1:7 NIV
For the Spirit God gave us does not make us timid, but gives us power, love and self-discipline.

I don't know how many times I have read the book of Timothy, but it is safe to assume I have read this verse more than 5 times.  At least.

So how did I miss it?  The Spirit God gave me gives me self dicipline.

So I must have self discipline.

Leaving the question, why do I not see self discipline in my life?  Why am I not using what God has given me?  How can I better tap into this resource in my life? 

I suspect the answer is that I will need to practice it. The more I use it, the easier it will become, and the better I will get with it.