I can't stress enough how important persistence is when picking up the guitar. You have a desire to play - the only left to do is to learn how to play. It's not easy (unless you're a natural of course ) and you need to be able to play something over and over and over until you get it right.
It's time consuming and you'll get better over time. There is no feeling like finally getting something down that you struggled with. So be ready to stick with it and put in the time - it'll come.
I'm a lefty too but play right handed. I always have though. You've got to play however it feels natural to you.
Dave
Guitars: Ibanez AF-75, Schecter Solo-6 Custom, Douglas SG
Amps: Fender Princeton 65, Marshall AVT50
Pedals: Metal Muff, MXR Smart Gate, EHX Cathedral Reverb, Digitech RP-255