Do you have a wife or anyone else who can turn on the breaker from inside while you are outside, listening? Does it pop instantly or after some little time? Does the A/C make a humming noise during that time?
iThe breaker has to match the A/C, you know.
I dunno, it possibly is not the capacitor. If you have a multimeter (as you should) with a capacitance, tester, you can test it (it could be bad at 220VAC even if tests OK by the tester, but still it is good to test).
Do not assume too much too soon. Could be that something makes the motor run harder than it should, for example. Some good investigation and careful writing down of the facts could help.
You may need to "hire a pro", eventually, but you would run less of a chance of being taken to cleaners if you form a good picture of what is going on. Or maybe you can just fix it.
i