Thanksgiving and Giving Thanks

On one hand, I am constantly thankful to God, or I would never make it through the day, I would be so down. On the other hand, I would say if I am lousy at anything, it is saying thank you to people in my life, quickly and directly. It has to be one of my most horrendous character defects. This happens mostly because I THINK I am going to say thank you in a most-grand way and plan it out in my head and never do it. I cannot seem to keep it simple. So, since I have come to notice this problem, my mission is to first of all, make all my future thank yous simple and immediate and second, to make amends and thank people I've seemingly forgotten.
The killer for me is, I've never ever forgotten. Each time I use a towel or a measuring cup I know who gave it to me and feel a tinge of guilt. I know exactly where my Cross pen and pencil set from my distant aunt and uncle are, given to me in June of 1976 upon my graduation from high school. They passed on years ago, of course. I especially hate how on my rehearsal dinner I thanked everyone EXCEPT MY PARENTS and feel like an idiot for it.
I hold on to guilt and shame WAY too long and it eats away at me, destroying my potential for relationships now. I build up stuff in my mind so high, I can never get over it.
This has to change, and it has to happen in a not-so-grand way, or I will never do it.