Scared of continuing CBT with self help book

Hello every body,

I have had depression and mood disorder problems that I "solved" in the recent years with CBT books.
But now since few months I am tackling the real problem : self low esteem.

I am using again a self-help book, and I did many progress but I am kind of stuck now
I was doing well in doing exercises etc. but recently I am scared to go forward, I even feel some sort of anger .
So I am thinking it 's really like my brain does not want to change, but still I don't understand why it's like that.
Specially this anger is weird and strong, I feel I want to shout very loud and kick things, which I do not do off course but still it's a lot of violence in my head. It's like when you are really pissed at someone, but I don't against whom and I never felt that angry before...
And it "goes away" 1-2 days after I stop thinking about the book or my low self esteem problem.

At the beginning I though it was because of quitting smoking (10 weeks now...) but it's really related to the therapy.

I don't know what to do, is it normal ?
is there something to do of being scared of changing ?
Maybe I am angry because I had low self esteem for so long and I am pissed at my self ?

I don't know what could help me right now, shall I try to just write things in a journal until the reason pops up ? Shall I go talk to a professional ?

Shall I just be patient and wait that things settle down slowly . I am maybe too hard on my self lately ?
For info :
I started a book on mood disorder in October = found out alcool and bad sleeping was bad for me and it's was related to anxious and depressive days. I quitted alcohol end of December.
I quitted smoking in January (with a cbt book only, no medication) and started a CBT book on low self esteem at the same time.

Thank you in advance for your help.