Well, it's obvious that the weightlifting is affecting your ability to sleep, so if possible, try to move your lifting sessions to earlier in the day - try getting up earlier so that you can train in the morning instead of at night. However, if you can't lift at any other time, then try relaxation exercises and breathing techniques to help you sleep, or have a short meditation session before bed. Having a relaxing bath with a calming fragrance (such as lavendar, chamomile or sandlewood) might help too.