For those who are croissant experts or bakers, PLEASE HELP!!?

okay, i am a young keen cook, i really try to cook and bake as much as possible, but there is one problem, i cannot make the perfect croissant. i have tried at least 10 times but all has not gone well on any of them. so i'll explain how i compete to make the perfect cressent roll: first of all, i weigh out 500g of plain flour, 2 level tsp salt, 1 tsp of dried yeast, 1/3 cup of sugar, 1/ 1/2 cup of whole milk, i mix together and wrap, i then beat 500 er with 2 tbsp flour and wrap it up and put it in the fridge to rest overnight, then i roll out the dough, and put the er in the centre and wrap te dough over the er. i roll it out and put the dough in the fridge to sit for 1-2 hours, i take it out and roll it, but there are cracks on the edge of the dough. i then do the famous single turn and put it back in the fridge for 1hour. then i take it out and rool it out quite thin but after all that chilling there is still er getting through the dough, i then do a double turn and split it into 2 halves and roll it, cut it into triangles, but i can't leanthen them, as they would easily tear, anyway i roll them tight into the croissant shape and let them rest on a baking tray in a turned off oven for about 2 hrs. i egg wash then and put them in the oven on 200 degrees and them bake for 10-15 mins. i take them out and i found the the er has melted and the croissants and baking tray are greasy. what am i doing wrong????