Three things you cannot recover in life, the word, moment, time so choose, embrace and never waste time arguing over things that will not matter in the last 5 minutes of your life. Always remember this. It's not worth it to waste your life angry.
Make sure that God is the one who shut the door. If God really did shut the door then stop banging on it. Otherwise, Matt 7 "Ask and it will be given to you; seek and you will find; knock and the door will be opened to you.