There are many ways to increase your bench press. Most importantly, if you gain weight, your bench will most likely go up if you are doing everything correctly. Another way is to switch up your routine. For example, you can switch to dumbbells or barbells for a month. There are many articles on this website alone that specifically focus on how to increase your bench. Just use google. Books can be written on this subject. The simplified answer is eat well, sleep, and train consistently, and your bench will go up.