What you did in the hour and power of darkness is not the sin that can't be forgiven.
On the night of His betrayal, Jesus told His disciples, "all of you will reject me this night," Later, before they did He said, "Watch and pray that you enter not into temptation, the spirit is willing but the flesh is weak." You behaved like His disciples, like Peter denying Him and face that your not able to remain in prayer without the help of the Holy Spirit and would end up rejecting Him. The grief you have is of the same kind as Peter and you must be a natural leader personality. The sin that can't be forgiven, continuing, to be filled with violence so that there is no room for Love of God. Evidenced by unable to forgive "For if you forgive not neither will your father in heaven forgive you. Think of it this way, you have a son who sais to you what you said to God, and then he is sorry, do you forgive Him. There is a huge difference between an outburst of anger sinning with your tongue and being filled with violence in the example of Hitler; one of his followers, met Corrie ten boom after the war, she remembered Him as one of the most cruel officers; he asked her to forgive Him, as he reached out to shake her hand, this was after her preaching on forgiveness, she could not but stretched out her hand towards His and was empowered by the Holy Spirit to forgive Him. Rest assured that your forgiven and if you have trouble with unresolved anger continue to admit it and ask for prayer. Judas is the example of rejecting the Holy Ghost to maintain His identity as a thief: referred as the son of perdition, later in prophesy this is referred as later as the man of sin, continuing to compromise with the sinful nature until taken out of the Way. The Lord is patient with us and not willing that any should continue to do so. Also the Lord has been patient with me that's why reassure you.