I Am A Male 53 Years Old Aproxmently 260 Pounds

I am a male 53 years old aproxmently 260 pounds 5:7 in height I have ED and have tried the pill none of them have ever worked I do still get an occasional erection won't last long enough or not rigid enough I have just learned of the shots please tell me the pros and cons it's been aproxmently 3 years since I had an erection maintainable for intecourse this has created problems for me my wife and our marriage