Hi Michaela,
We have also struggled on and off with the early wakings. I find that putting him to bed earlier, even by 15 min., can sometimes make a big difference. I have also found that by not leaving his room when he wakes this early helps to not reinforce it as well. So when he wakes I would go in and tell him it's night-night time. He would usually want me to pick him up which was fine, but everytime he asked to go downstairs, or that he wanted milk, or that he wanted Daddy, I would just keep saying no and that it is night-night time. He would cry and carry on, but I was right there with him, and once he calmed down I would put him back down. Some mornings he would go back to sleep, and other times he would be quiet for 20-30 minutes or so and then start back up again, and if he did I would go back in and do it all over again. Within a couple days he was back on track.
Hope this helps a bit, and remember you are not alone!