1) Clomid isn't garbage
2) Two weeks after last shot you start PCT
3) You will not gain 20+ lbs of muscle from 275mg of Test C/ Don't taper, it won't help you will be already shut down. Tapering won't help.
4) You don't sound like you have a firm grip on bodybuilding yet. And being 151lbs @ 5 11" you should stay natural for a good few years ? and up your calorie intake.
500mg w/ ~3500kcals