6 weeks into my upped dose - you are all the only ones who understand! Advice?

Im 6 weeks into my upped dose of 20mg. Have been on citalopram all in all since the beggining of may and I started on 10mg.
For the 6 weeks I have been extremely irritable - my moods are awful which i never experienced on the 10mg.
Im so worried the meds arent working.
My question is, is this usual? I feel like a horrible person and I so need some reassurance or similar experiences :(
I feel i can only talk to you all!
Thankyou x