Make a list of 50 things that, if you really were successful in doing them, you would be a better person or a better company. Then, from your list, choose one or two that you are willing to do within the next 90 days. Schedule those one or two new activities, then go for it. Afterward, choose one or two more and do it again. Make personal and professional growth a lifelong habit.
Most businesses take on any client who steps up with the money.
Consider the cost to you for dealing with the people you serve. These are the people who give you energy when they are near you. On the other hand, there are probably others you can think of who drain all the life out of you. Get better clients. You deserve it.