Go to a local gym and find a trainer or someone who seems knowledgeable who might be able to sit down with you and SHOW a good 5 day workout routine, paying close attention to TECHNIQUE. Just like in fighting, good technique builds more power and muscles.
If you want more info, more detailed, pm me
For Sekou, careful with the sandbag throws as people who just wildly throw the bags can and will hurt their backs. One of the things we do is swing a 20 pound sledge hammer at a tire (even into the ground might be safe for your body)50x swinging from behind the body and downward and alternating with each arm. I do this in addition to my arm weight lifting workouts