So, a few things are jumping out at me right off the bat here.
First, the spaceplane look HEAVY. Like, really heavy. This could certainly be working against you rather than in your favor.
Second, I notice that your engines are very high up. None of the images seem to indicate the "center of thrust", but if it's too far above your center of mass, then it's causing a pitching down moment, which would put pressure on your nose gear, and would cause tilting and skidding, as well as make it extremely difficult for you to even lift the nose off the ground.
Third, you might try increasing the angle of attack of the main wings by rotating them upwards slightly, so that the wing is attacking the air at a greater angle than your nose. This will give you added lift before you even get the nose off the ground.
And finally, I am not sure how you have your control surfaces set up, but that main wing won't do much to help you pitch. Your only hope would be the canard wing near the nose. Make sure it's large enough, and bound to the pitch axis.
