I truly cant convey how honest-to-god, sorry I am to hear this, Steve. I cant sit here and say I know how you feel, because I haven't had to endure such a deep and very important loss such as losing a father. Hate to even really think of such an awful situation to be honest.
But what i can say and offer, is unconditional sympathy, support or even just an ear to listen. I extend to you, your family and anyone else affected by your father's passing, the deepest condolences. But namely you directly my friend: hang in there, even in the most unsettling of times and keep the good times you had with him alive with you everyday; never live a second dwelling on any regrets or what-ifs.
Always here to talk if you need somebody my friend!