It's lasting a full 2 weeks now. I'm hopeless, no motivation. Nearly weeped this morning when DC didn't come in when asked. I feel like I loose all control. The house looks like it's been burgled, the DC had to make do with cheese on toast for tea, there's no shopping in. I just feel utterly useless, now I'll have a week of back cramps and feeling exhausted, then on to a week of feeling like superwoman, everything getting back to normal and sparkling, enjoying the kids, just in time for the cycle to start again 
What's happening?? I'm sure it never used to last this long...