DS (nearly 3) seems to spend all his time hitting, pushing, biting and throwing things at DD (aged 15 months). I know there's a jealousy thing there, and have been really trying to give him my undivided attention whenever I can (eg DD's nap times) but it just never seems to be enough. Today he has driven me to distraction, and he's been in his room to cool down about 5 times. I feel as though we're getting into a negative cycle, and I'm getting really angry with him at the drop over small things. This is all made much worse by the fact that DH has had a virus for about 3 weeks now, and hasn't been able to help much as he's feeling so rough. What can I do to make things easier?