Being strong at bench press and building muscular pectorals are 2 different things.
If your focus in the past has been on low rep bench press then perhaps you need to increase your reps and put your focus on squeezing your pecs rather then worrying about how much weight you can bench.
If you get nothing out of the barbells then switch to doing more dumbbell work in flat and low incline. Weighted dips may also be of benefit to you if your shoulders are able to cope with the movement.
You also might want to try pre exhaust techniques. Some guys like to hit pec deck before doing any bench work. Personally I get nothing out of pec deck but still you need to try a few things and see if you respond.
Dumbbell flyes before doing Low Incline DB bench can work well.
Basically you need to focus on the mind muscle connection and try and squeeze pectorals rather then push weights.
Once you develop a good mind muscle connection you will most likely feel your pecs a lot more when doing bench press. Squeezing the bar inwards can help with this as well. You wont be able to lift as much weight but then again who cares about the weight you lift if your goal is muscular pectorals?