L.S.
My son would always get extra fussy right before some big developmental milestone such as crawling, walking, nap changes, etc. Is she talking? If not, that could be part of the frustration as well. My son responded very positively to signing. It really helped him a lot. Playgroups also kept him happy too. I don't know if you belong to any, but that might be a good option for both of you (playgroups are sometimes more for the mom than the kid). Another thing my son liked, especially when it got hot, was to play around in some water or at the sink. I dont' know why, but he really liked it a lot and it would calm him down. Play-doh is also good for him. Both can make a mess, but I always considered that a small price to pay for some peace.
Good luck. It will pass.