A lot of people are doing that too, it is not only you who prays when they are at their lowest point of their life. You know, praying while you are in your saddest moment of your life helps us release our stress, anxiety and tension. It gives us the way to connect to God and expresses our feelings to Him. It is also good that you pray, it is a good indication that you still believe in Him and even you don't go to church and reading bible, the faith is still reigning in your heart. So don't worry too much about that. Cheer up and live life to the fullest.