What is the best way to get back in the gym?

Wow, as a person who basically grew up grappling I began to lift weights when I went into the Navy. While serving in the Persian Gulf and Mediterranean Sea I found weightlifting to be both relaxing and a huge stress reliever. As I aged I used weight lifting as an escape and a maintenance program for both my body and mind. I regularly went to the gym although I didn't really mingle or socialize I enjoyed the scenery and the atmosphere that was associated with fitness. I saw the GTL's come up, the hard bodies, and the meatheads. I saw the weight-loss fanatics, the cardio animals and the time passers. All of these people made my day at the gym enjoyable between sets and exercises. I loved the feeling of the pump and the effect it had on me.
 Then one day I went to an academy (I am a BJJ/MMA instructor) of a world renowned competitor and asked him about his workout schedule. His response startled me. "I don't go to the gym or use supplements. I just do jiu jitsu." This completely changed my whole thought process. I had been following and implementing this person's style and game plan so thoroughly that I actually almost felt brain washed. I said to him "you never go to the gym?" His response "nope never". So guess how crazy I am? I stopped going to the gym.

 Fast forward two years. I am the heaviest I have ever been. I'm not fat by any standards but I am getting a little pooch and my arms are shrinking. So being the hard head I am I decided to get back in the gym. Let me tell you what it was like. I was physically stronger than I had been before. Cardio wise I am great (I ride my bike to work) and talent wise I don't want to toot my own horn but I have great form and understand the physiology of weightlifting. So where is the down side you ask? My body feels like I got hit by a truck, then backed over and groin stomped. Then they picked me up and threw me into a cactus field. My question is how do you get back into the routine through the pain? I'm talking real pain.It is really good to work hard and achieve a goal but man, the pain.