Even though it may be difficult to get in touch with a doctor, I do suggest you see one for advice. If you have had a heart attack, no matter how 'minor' it is, you need to eliminate certain risk factors that you can control (like weight, diet, habits, etc). Weather mountains are off limits or not, depends on your current condition - which only a doc can tell you.
As for insurance, it all depends on what you have been diagnosed with, any medications that you take, etc so we can't tell you for sure.
I do agree with realc4ever that you need to eat better. However, you need to know your actual condition and risks before determining what activities you can and cannot do.
Wishing you well...
"Don't just think positive, BE positive."