My own worst enemy

Hello, I am new to the program (just this month) and I have already learned so much but mostly how to be aware of my thoughts. It scares me because my thoughts are so negative and fear based that I am my own worst enemy and my own major obstacle to overcome to succeed.
I was married for 32 years and was mostly a stay at home Mom. My children are grown (33-31) I got sober in 2007 and 6 years into sobriety I realized I wanted to leave my marriage. I know now that you say this is a choice to fall out of love which I tried to fall back in love with him but it was just gone. I have been on my own now for 3 years. I dont miss him but I miss the security of someone taking care of me. Im lost, scared and overwhelmed. The finances were not what I was lead to believe they were so I had to get a job. I got a job barbering (I am a licensed hairdresser since I was 17) but I really dont enjoy it because of my lack of confidence and age (55). As soon as a client leaves, even if they are happy which 99.9% of them are I start to go over what I did wrong and beat myself up.
I ended up with some female problems so I just had a hysterectomy and I am off (without pay)for 7 weeks which is when I found you and joined. This is my job this month. I feel so blessed to have this time to look at myself … well I am taking the year for me with your course and investing in my brain, I cant afford not too!!! I had a melt down just before I left work which was anxiety over my job.
My clients like me and my coworkers love me but … I cant find it in me to accept I am capable and can do this. It got to the point where I was so low I thought I was going to mentally crack and end up in the hospital. It was terrifying.
How do I get out of my own way, stop needing peoples approval and know how great I am … because I am and I have so much to give.
Thank you in advance