When you are doing your rows try to pull through the elbows, instead of the hands. Feel and try to visualize your lats activating. Basically, try to row the bar to your stomach and they're should not be a lot of elbow bend. When you get to the contracted position squeeze hard for 1-2 seconds.
Switch to pull-ups (overhand-grip; pronated-grip), instead of chin-ups (underhand; supinated-grip). Pull-ups will take the biceps out of the movement and make it more forearm, back focused. When doing pull-ups tuck in your elbows during the movement. You should feel your lats activating more this way too. Also, when you're in the bottom position of the pull-up hang until your shoulders feel like they're going to dislocate then pull back up.
As for your chest. Keep upping the weights, bro. Ask for more advice on chest training later. Everyone on here will tell you, that your chest is not growing, because you've only been training for 3 months. When you get to 50's your chest will be bigger.
You said your weights have been stuck. I want to see your current program then maybe I can help you.