True Serenity

I am sure everyone who believes there is a God has a plaque somewhere in their home and/or workplace that reads as follows:
"God,
Grant me the Serenity to accept the things I cannot change
Courage to change the things I can
And the wisdom to know the difference."
Now, this is indeed a noble prayer, in my humble opinion. However, does that truly define serenity? What does that word truly mean? If defined solely by the context in which it is used in the above prayer, then I am forced to conclude that it is somewhere along the lines of "peace of mind". Webster defines its root word, serene, as
1. clear, unclouded
2. undisturbed; calm
Okay, all definitions mean pretty much the same thing. But is serenity simply about acceptance? My experience forces me to conclude - certainly not! Lately, I have been feeling, well, UN-serene! And not in a good way, I might add. Sure, I am looking forward to Carnival. Sure, I am a college grad earning money by working in the field I studied for (a scenario, I am told, that is very rare - ironically). I am blessed in more ways than I can count. I have accepted Jesus as my Lord and Saviour. I have accepted the people in my life as who they are. I have accepted that I may not always get my way. I have accepted that sometimes, life is not fair. So, why the UNserenity? Why the inner turmoil? Why am I angry at myself for not doing the things I want? Today, at church, I sought guidance in an elder (who I respect and admire dearly). I poured out my heart to him about all the confusion, anger and anxiety I felt within me. All he had to say was this: my thinking was off. I was thinking about me, and me alone. At first, I was like "okay?" He went on to explain that if I truly loved God (which I do), that I would live the way He wants me to - and nothing else would matter. "Seek ye first the kingdom of God, AND His righteousness", we are told. But it is not just a commandment alone. There is a promise attached, which says "and all these things will be added onto you." I must have sung that line a million times, but I still didn't get it. The reason for that is painfully obvious - I was just singing it. I wasn't living it. I am not claiming that a lightbulb suddenly came on and I am now completely enlightened. That's rubbish. But I will say this - that certainly helped. My faith has been rekindled because now, I have been shown the way. I have simply to tread it to gain some sort of understanding. Perhaps in living this way, the answers will come. However, this is by no means some magical process. It takes time, endurance, patience and, above all, FAITH! I cannot wait until I "feel" right in order to begin - I could wait forever for that feeling, and I am certain that God didn't create this creature to simply wait around and cry! So, here goes. Time to live for others who need God's love. Time to give my life purpose. Whatever it is, let it be all about God. The rest, I believe...I KNOW...will follow....