There is no such thing as an aggressive baseliner at 3.5. You need to stop trying to hit hard and through a guy who gives you no pace.
I just played a pusher last week and barely lost a point. I play baseline tennis too. You need to hit very relaxed and just focus on making clean contact. Hit at 60% of your power and move the guy around.
Notice how when you dont get pace, you tend to make errors? He will too. Pushers love pace, so dont give it to them.
Hit relaxed balls that are placed well. Keep them safely in the court but attack his weak side and hit that corner. As soon as he starts running to get one, you need to move in. Take the next ball just as relaxed and put it to the other side. Move in some more. Take the next shot as a volley and put it away.
Thats how you beat a pusher.