Unfortunately many things could have happened that contributed to the bad shot.
1. You indicated that you were not confident in the rifle as you had only owned it for a few days and had only taken it to the range one time. When we have a lack of confidence in our tools, i.e. hunting rifles, we inherently tend to have a lack of confidence in ourselves. We begin to second guess our decisions and capabilities with an unproven rifle. This lack of confidence in turn causes us to hesitate or waver when it comes time to act, i.e. holding your shot just a little longer than usual could of allowed the doe that extra step that placed your shot too far back. This is probably the main contributor to your problem.
2. You stated that the wind was blowing and that it was sprinkling. Either of these could of have also been a factor in the bullet hitting to far back. What type of experience do you have shooting in windy conditions? How fast was the wind blowing? Which direction was the wind blowing? Was it gusting or was it a steady wind? Please dont take this personally, but most hunters today do not know how to properly dope the wind when it comes to shooting. Depending upon wind speed and caliber a bullet could have moved as much as 10-12 inches in a stiff breeze at 145 yards. Larger, heavier bullets will drift less than lighter, smaller bullets but they will still drift to a certain extent. Also how heavy was the sprinkling? Just like a bullet can be deflected by the tiniest of limbs, so too can bullets be deflected by rain drops. I know, I learned the hard way on a Utah mule deer hunt 3 years ago.
3. Finally, because of your lack of experience with the rifle in question and its trigger mechanism, you may have jerked the trigger a bit too hard, thus causing a change in the rifles aiming point and not even be aware of it. Even when we can shoot a rifle well from the bench, the excitement and adrenaline rush that occurs when we finally have our quarry in our sights can result in jerking the trigger or over compensation for expected recoil.
Bottom line is you probably need to spend more time with this rifle at the shooting range so that you can become familiar with it and its own personal quirks. Then after you have built up your confidence and ability in the rifle something like this probably would not happen again. Good luck and happy hunting.
P.S. Where in east Texas did you go hunting? I am always looking for places closer than the hill country.