Why does it seem like the universe is fighting me?

Starting to question my drive. It was there last week...think it just kept on driving without me. But, knowing myself as I do...it's that time o' the month. And, I don't bring it up for excuses, although it does provide them, and I have succumbed...but just facing some facts here...
I AM HUNGRY! I wasn't last week. I did my Slimfast, ate sensibly, no hunger. I was suprised. Then over the past day or so...the appetite has increased. Like, I could eat paint chips or chew the sheet rock off the walls. Try to make healthy decisions...but when money is so tight that your trying not to change your child's diaper too often, healthy purchases (on top of seperate foods to feed the kids) isn't really an option. So, trying to make those better choices...and sometimes doing well, sometimes not.
And another thing, I am just tired. Again, got sleepy a bit here and there last week with waking early, watching calories in and out...but now, even with sleeping later than I was...I'm just whipped.
So, no, I don't think it's just mental. I actually googled it and got some scientific possibilities of why...not to bore the audiences and keeping it general, (if I have any), but it has to do with hormones dropping your blood sugar.
So, should start sometime this week or early next week. Dunno what I'm going to do this week as far as working out and stuff goes. May try to combat these cravings and tiredness with militant precision...or may just cut myself a bit of slack.
Older kids are going to VBS, and the younger 2 do NOT do well in the stroller for more than 10 minutes or so. Oh, what I wouldn't give to join a gym...and it's not the gym fees that are the issue...most places around here, I could join for $10-15/month. But, it's the childcare fee that I'd have to come up with on a 5 or more day basis. There's just no way I can do it. But, it's so hard to incorporate working out the way I need to do so with little kids...it's not impossible, just very very hard.
So, yes, in my woe is me...I am in the depths of ...it's so much easier to be fat...why not? But I don't want to be fat, and ultimately -- it isn't easier. But, I swear, it feels as though the universe conspires to keep me here.