We all struggle. Each time I come to the canvas or paper I wonder... can I do it again? Or was that last painting just a fluke? That struggle, filled with anxiety and self-doubt, can bring on some very un-useful and darn right negative side effects.
The first I will address is excuse- making. It is one of the biggest things you do to stop yourself from succeeding. Great talent and hard work are not enough. You have to make choices and give up other things. You have to have priorities and try your very best to live by them. You need to take risks with your work and risks to put yourself out there. They will not come to you.
Excuse-making blends right into risk taking. We make excuses when we don't want to take the risk to succeed. The biggest excuse I hear is "I don't have the time to paint." We will allow anything- doctor's appointment, the dishes, an injury or the dog, to get in the way of our painting time. But there are no excuses. My advice for this one is simple... just schedule it. Just like you go to work, when the scheduled time comes you go in the studio/your workspace no matter what. Do not open the computer. Do not check your phone. Sit and be until work finally starts happening.
I remember, a couple of years ago, when I interviewed Deborah Paris and she said "For five years I woke up and began painting at 4:30 AM, finishing just in time to go to the office. I also painted on the weekend. I sought out drawing groups. In a short time I knew that landscape painting was my muse." (Check out this three part interview for a good read- link here.)
Lack of time IS an excuse. We all have little time, yet we find time to do others things (TV, computer, movies, going out to eat) You have to set your priorities. I am not saying to become a recluse. Instead remember you are always making choices.
There are other excuses- space, materials, money, the buying public, and many more. They go on and on. So what do you do?
Set your intention and stick with it.