You already made a huge step in the right direction by lifting weights: not only will you lose weight and get stronger muscles that will support your back, but when exercizing, certain chemicals are released in the brain that help fight depression and lack of energy. By doing this, it will be a lot easier to reach your other goals than when you had put 'get in shape' on the bottom of your list. If you want to drive somewhere, you need to fix your car first
Keep going!