Change your diet, change your life - avoid stress, stressful people, stressful situations, Doc will probably put you on a low-salt, low-fat, low cholesterol diet (not as bad as it sounds, easy if you or the Mrs. does a lot of home cooking - tougher if you eat out a lot)
Depending on precisely what happened, they may put you on meds (325 mg aspirin, plavix, lipitor all sorts of fun things) and will check progress on regular blood tests. You may carry nitro tablets or an inhaler. Might want to learn a few basic medical tasks (how to take your BP for one, Lumiscope makes some handy electronic testers that are reasonably accurate - although should be checked against the Doc's)
Do learn about the warning signs and do take them seriously, you can be a dead tough guy or a living wimp (by going to the hospital when you feel things going wrong) Don't overexert yourself and heed your Doc's advice on any exercise programs.
Sometimes a little heart attack earlier is better than the big one later - you likely have a chance to change your habits and avoid the latter.
Good luck!
ETA: Find something soothing for a hobby, fish can be very relaxing, or gardening, or classical music.