My working day (plz help me to correct)

I've just finished my working day. Today I'm kind of busy. I ve worked here for almost 6 months.

I think this period is not short but i am still feel like i am a new comer, just because i still dot get used to the job.

I know that the period that I have worked here is not short, but I still feel like a newcomer since I am still not used to my job.

Everything is still a mess with me./ Everthing still seems confusing to me 

Sometimes I let my mood fell down since I make many mistakes, most of them from my carelessness.

Somtimes , I become moody when I make a lot of mistakes , most of which are due to my carelessness.

Knowing about myself, Ive been trying, but the outcome is a bit lower than I want.

knowing myself well enough , I have been trying to improve , but the outcome is still a bit less than desirable.

My manager must be frustrated with me, but he said nothing. I rather be scolded,since it will help me remember my faults.