NO, don't even think of EB3 if you have the Masters from US. The priority date is current in EB2 for Nepal. Go for your I-140 and I-485 right away after your labor is approved. I am giving you my timeline, but that's pretty much the same for friends and folks who filed together with me.  

Labor = 45 days

I-140 = 96 days

I-485 = 138 days

So, you can see it’s not even 10 months overall. It’s really that simple in EB2. Get the best lawyer for yourself who can walk you through the entire process. My company was paying for it, so obviously I got the best one.