With me I didn't have all the right stuff to finish my projects, and this worked out for the best for me, cause I've learned so much in-between, that if I had finished them, I would of been disappointed.
Bruce-Slug said the right thing, you are to enjoy the hobby, if one model starts to get you down, put it a side, and start on another one. Put that one in it's box and save it until your ready to tackle it again.
After a while you will be, after working on another one, and having much better luck, that will built your self confidence to go back. I have done this many times, I have sanded and sanded, then finally I found a place where I never glued the seam, so it never would seal, so I got that straightened out, and shot with primer, and now it is finally smooth, but it took 4 or 5 tries before I notice that seam, it was real hard to see, the way it was built.
But I put it up until I was ready to tackle it again, and worked on something else. I'm not sure but I think I got about 16 or so going on at once, at a quick glance, to keep me interested.
Kerry