Searching for a well

I'll preface this by stating (what I hope is) obvious. I love my son. I cannot imagine life without him, nor do I want to.

     But there are days when I think I'm just going to lose my shit. And now that he's 2? It's happening more often. He's so physical. Pulling, bouncing, touching, throwing things. Constantly. Sneezes on me, wipes dirty hands on me, dumps juice, water, cereal, what have you, everywhere.
     I know. I KNOW. This is what they do. And most of the time, I can roll with it. I get it. He's learning. He needs to touch, feel, explore. He needs to be told what's wrong, what's right. And he's a smart little booger. So he gets it.
    But me. What about me? (She whines selfishly). I have days where I have no patience for this. I don't want to be a mean snarky Mama, but geez!!! How much pizza sauce do I have to wear!!!! I close my eyes, and imagine a deep blue well of patience. And I need to draw up another bucket before the rope snaps. And some times that rope gets pretty frayed.
     His hours at the pre school do help. I miss him during that time, but I also get some personal space. I've had very little personal space, lately. I'm wondering if I should start picking one or 2 days a month to send him to pre school for a few hours on my day off. So I can have a whole afternoon without any demand, work or kid. Will I feel guilty doing that? Probably. Especially the first time. I'm guessing and hoping it will help me replenish my well, though.
I'm open to any other ideas and suggestions though.
Or you can tell me to shut it and suck it up..,