6 month old is irritable and frustrated! help!

Hey all! My son is 6 months old and he has been trying to crawl recently and had two teeth coming in. He has been extremely irritable and gets frustrated when playing among other things. He has been demanding food and when I don't feed him fast enough, he gets ticked off. I am just wondering if this is normal for a teething child around this age. I feel so bad because I feel like I am not doing something right.