Identifying Feelings and Anger at Work

I’ve been working on identifying my feelings. Sometimes my boss gives me assignments and when I am working through them, I feel somewhat angry and irritated – with the assignment, with the way things are done at this firm and in the industry I work in. I don’t want to do the assignments and find all kinds of excuses not to like watering the plants in the office. I try to make myself do it but there is a lot of resistance. I did a model:

C: boss gives me a new assignment
T: This is a ridiculous way to do this. I hate the way they do things here. Maybe I am working for the wrong firm.
F: annoyed/ irritated
A: water plants, go to the water cooler, try to make myself do the assignment, do a little but get even more annoyed
R: I do the assignment in a ridiculous way or not at all properly.

It does not make sense to me to be angry at the firm but not at myself for not doing my job properly. Is this really anger? It is the same feeling I get when I speak with my mum on the phone sometimes and I get annoyed.