1. If you continue to see an ophthalmologist yearly and follow up with the retina ophthalmologist whenever he/she recommends you have about a 99.5% chance of dying with good vision if you live a normal lifetime. This also takes into account living a healthy lifestyle: exercise, good diet, not smoking tobacco or marijuanna, not alcoholic, no opioids/narcotics, etc.
2. Lattice is NOT a big deal. It's found in 6-8% of the population depending on how hard you look for it. I have lattice in both eyes and have never had a problem. It is higher % in myopes
3. Lattice does not occur in central vision. It generally does not progress. The treated areas are STRONGER after treatment than before. no cause for concern
4. Hopefully you will only have to have the one already done. Some diabetics have scores of laser treatments. Again not worth worrying about.
5. Heavy weight lifting does NOT cause lattice. However it is possible for a person with high myopia and severe lattice to cause a tear within the lattice by lifting to muscle failure. You will need to ask your retina MD about continuing to do power lifting. I personally don't think it a good idea, neither are contact sports, if you must do contact sports proper eye protection is a must. Avoid carnival type rides that whip and jerk your head about.
Compared to a lot of people that post here your problems do not have grim prognosis.