I would second the idea that you should send it back to be evaluated and potentially rehoned. Having an expert look at it will tell you for certain if the edge is good enough to shave with. There are a thousand reasons why it may not be. You need to know that the edge is ok so you can eliminate that as a potential variable. If the edge is ok, then you have to focus on your technique.

Variation in angle and pressure is much more subtle than most people realize, and the learning curve is largely about learning how it should feel and what the feedback means when it feels wrong. In fact, there is probably no such thing as proper angle and proper pressure. They are just continuous variables in the process. Getting to know how your blades respond to your face is the education required to shave with a straight.

I don't know if it's possible, but it would be nice to find a barber that can shave with a straight and have him shave you with it. That way you could prove on your face if it is the blade or the technique. Short of that, you can have someone else that has coarse whiskers give it a try. There are a lot of good people on this site, and I'm sure that many would be willing to help you out.