I've always had the same body type as you and I agree it can be frustrating. You have to give it time. Since you've been training you've never even made it two straight years and you even said your diet isn't all that great. Research all you can about aas and if you truly understand what you're researching then you will realize it will be best to get some more natty reining done.
Just keep training hard and eating big and the results will come. Trust me I've experienced it and so has every other member here who hit a plateau.