Talking myself out of discipline

I apologize, faithful few, who read my blog. It has been a rough week for our family, with illness and difficulties with financial loopholes, my mind has been preoccupied. But, since I made a commitment to myself that I would blog 5 times a week in an effort to make it a spiritual discipline, here I sit typing away. It has been so easy to talk myself out of doing this. I have had every reason not to do it, yet, I decided to say no to my flesh and say yes to my commitment. It is not easy, but I made a promise to myself, and anyone who knows me knows my word is good ( although that is quickly falling away by the wayside in today's society). Why is it so easy to talk yourself out of discipline? Why is it even harder to talk yourself back into it? Is it because " my mind is willing, but my flesh is weak?" It's a hard one to call.  Why do I commit to regular exercise, yet only to give up a month or two later? Does anyone else struggle with this?