Ask your instructor if you could put post-it notes over the instruments you shouldn't be looking at (pretty much everything but the ASI, altimeter and DI at this stage) thus giving you no choice but to keep looking out of the window.
The instruments, at this stage in your flying, are not your friend. It is very important to keep your head out of the cockpit as far as possible. For anybody who has done much PC based sim flying, this is very counter-intuitive.
Overall however, your level of trouble at the moment sounds pretty typical for a 5 hour student - it'll come, just relax and enjoy the learning process. The odds are that the thing your instructor is most worried about is over-analysing the flying rather than just getting on with it.
The differences between a C150 and C152 are significant enough to disrupt the learning process but, to be frank, probably not with the few hours you've got so far. I'd do your best to stick with the same type throughout your training - and the C152 is the easier aeroplane to fly, but again not over-analyse the differences from a couple of previous C150 hours.
G