overdue - please give me positive natural birth pep talk :)

Elizabeth
Hi Peeps!
I'm 40 weeks and 2 days and haven't had any labour signs so far. Although I'm fine with that and know my baby will come when ready I have noticed a REAL change on myself.
Over the last 2 weeks I have steadily become exhausted. My mood is very low, I'm sick all day in my mouth and am constipated. I know this is all normal but I feel very..... disconnected suddenly and like I'm also checked out from the end point.
I want a water birth and so can't have an epidural. For some reason, my low mood has suddenly made me lose ALL confidence in my plan and my ability to get the energy for my labour. I feel like I am so tired I won't deal with anything and I am usually an extremely positive, brace person! Has anyone experienced this?
For those of you that went natural, please can you give me a little pep talk to say I can do it and my mood will rose ready for the even? It would be so greatly appreciated I can't even tell you.