I faced (and face) a great deal of anxiety when it comes to attending classes and exams. I should be out of university already but I keep failing: it's a painful reminder of all my shortcomings and I dread it. I started vomiting before exams from pure anxiety. For two years, I just stopped going.
Praying helped me a lot. I know I have to go through it, to finish something for once in my life. I know I shouldn't flee again. I went to the morning mass and afterwards I stayed in the chapel and just repeated over and over again: "Jesus Christ, my Lord, keep me company in my suffering and let it be and offering to you". After and hour, I mustered enough courage to go to the train station and board it. I had planned this many times before, but never actually done it. I kept praying in the train, and then in university, while I waited. The teacher eventually arrived and the class started, there was nothing special abut it, nothing particularly exciting, interesting nor anxiety provoking.
It's not bad to lack strength cause anything you try to do on your own will eventually fall down. Learn to rely on the strength of the Lord, to do His will, to be His tool. You'll find yourself easily doing things that were almost impossible before.