Terrible Twos

[ally]

Ok, need advice here!!! Ok, so as many of you know I've been at uni for the past three months & Leo (now 2 & a half) has been goin to a childminder's, I've only really been spending time with him on weekends. Now I'm on holiday & I've got him with me all the time I'm finding it realy difficult to keep my temper. I don't knw what's happened to us both over the past three months but I feel we've both changed tons. I'm trying my best to do 'interesting' stuff with him, like make cookies & xmas decorations, but he's a bit young for things like that & ends up making more of a mess than anything else. he's constantly saying NO to everything i say & he's doing stuff he knows he's not allowed to do, while looking me straigh in the eyes. I've lost my patience a few times now & smacked him (the one thing I never wanted to do as I've always really resented my own mum for doing this to me as a kid) & now he's taken to hitting me, even when we're having fun. Arghhh, do all kids go throught this stage (how long does it usually last) & does anyone know any good techniques for staying calm?