I need constant motivation…how do I take action on my own

In many situations I realize when someone else motivates or says ‘hey you can do this’ I feel so energized and get things done. But times when I have to convince myself I can do it I hardly succeed. There is lot of self-doubt that I can achieve the task. Practically it is not possible for someone to motivate me always and I don’t know how to convince myself that I can handle a problem. I do thought downloads and model my thoughts but I find it so difficult to believe the intentional model. Even if I come with ladder thoughts my brain keeps saying there is no way you are going to handle this. You can’t believe something totally against your belief system. How to effectively model my thoughts since there is so much resistance to adopt new thoughts…thanks so much !!