One of the enemies of being creative is just not wanting to do the work. You could call it being lazy, but I don't experience it like that. It is easier to just be normal, or like everyone else, or to copy someone or something else. Being truly creative is hard work and I think many times we fail to be truly creative because we don't want to do the hard work it requires to truly birth something new and different. A variation of this is to create something like what you have already created. In this case, you are just copying yourself. Unfortunately, our society sometimes rewards that. If we create something truly new and original, our society sometimes wants more of it and we are left with little option than to go ahead and make something similar. Hey, I've done that because it pays the bills.
True creativity means being willing to do the work it requires. Just go for it and do the work. Don't avoid it. If you have to pay the bills, then go ahead and create something similar to what you have already created, but get started on something new and different as soon as you can. I guess it is a matter of courage. I have also found that the more you work on something different and original, the easier it becomes to start and create something new and different.
Do you want to be remembered for being average or not being able to break out and do something different? Go and start something new as soon as possible and do the work. In the end the reward is worth the effort.