My alekhines defence game

i couldnt figure out how to annotate sorry guys but ill give it a go here

opening is alekhines defence marcosy variation

move 1 to 6 im tryin to develop my pieces and by this point have a decent presence in the centre. 6...a6 was preparing for a push to b5 also preventing the knight comin to the same square

whits it seemed wasnt prepared to open up for an attack so i continue expanding my goal to allow myself eitherside castling as to undermine an eventual attack after white starts a kingside storm and decides to attack my kingside i castle queenside.  at this point i feel his army can only really attack with one piece (his knight).  after a minor exchange im feeling quite confident and by move 18 have a lovely knight looking after my queenside, rooks redy to line up, and all exchanges seem to be on my terms for now.

i decide to sacrifice my knight to open up whites position further however he declines and his coming attacks while at first looked sure there was a forced mate on it was readily thwarted.  by removing whites dark squared bishop im happy simplifying and getting to an endgame

as far as the end game goes i end up down a pawn and cant really see still where it all went wrong in the exchange.  someone will have to tell me if its winning for white from there or not but i managed to get a blunder out of white giving me a queen and shortly after a resignation.  

ultimately i feel from my position at move 16 i should have won a little more convincingly. Id like to know where it went wrong also if white should have won the endgame or forced a draw ect.  this has to be the most complicated position ive ever played from and found my options overwhelming at times and most likely blundered my way through. 

This isn't an Alekhine. After a few moves this is a fairly harmless closed Sicilian.

To be honest, most of the moves played by both players did not seem reasonable to me, but the most hilarious part was the endgame, where white managed to lose  a much superior (probably winning by force) endgame within 5-6 moves.