Your toddler is doing very well in being able to fall asleep anywhere. Honor that. Take a few moments to really rejoice in that. Many toddlers/babies need to be by mom when they are falling asleep.
When he comes into your bed in the early morning hours, he is truly in need of your presence. Is it possible that you could honor that? Since he is truly in need of that, is it possible you could dig down deep inside you to find that you can, afterall, meet this need of his? Usually, we panic, worrying that our child is maladjusted or will be doing this forever. Let me assure, you, it won't last forever! When he feels secure enough (and this is something inside him), and that might be months or a few years, he will no longer come to your bed. It will probably be a gradual process until one day, you realize that he hasn't come to your bed in weeks. Even then, for some reason when he needs it, he might revert to it again, but eventually, he will stop. One day you will remember those times and wish you could have it again!
When you are in the midst of it, it feels like you just can't get your own space. Whenever I felt that, I would pretend I was still pregnant. I had no choice then, and now, in this moment, pretend the same. For even though he is no longer sharing your physical body, he is still sharing your energetic body and needs to be near you every so often to re-energize. Since you don't get to spend too much time with him, isn't this an easy way to give him some of that time that you don't have otherwise to give? Sometimes, just looking at it from another perspective can help. Blessings to you.