I have a 9 year old service dog I adopted when he was 12 weeks old. I went to school for dog training and I trained him myself. Best thing ever. He helps with nightmares, anxiety attacks, self-harm, and so much more.

My service dog turns 5 on Friday! It's a ROUGH process, but totally worth it in the end. My dog has saved my life many times in many ways. I wouldn't trade that struggle for anything. To answer your other question, service dogs generally need (minimum) 2 years of training. My pup spent just over 2 years initially training just to be ready, and has had a few refreshers along the way. We're always training, of course, but we do a mixture of owner training, professional training, and board and train. For reference, I have spent more on my dog and her training than I paid down on my house. It's not easy and it's not cheap but if you think it would work for you I'd go for it. Just don't fall the for the online scams where you just buy a certificate. Those are fake and awful. Please research the steps of service dog ownership and the difference between service dogs, ESAs, and therapy dogs thoroughly. Good luck!