A couple of things came to my mind after reading your post:

First, is there something in particular waking you up in the morning? Traffic noise? Neighbors? Sunlight? (Not sure what time you would prefer to get up.) If you notice anything in particular that might be waking you up, that would be the first thing to try to remedy.

Second, you mentioned that you get up to go to the bathroom during the night and you take melatonin. Can you adjust when you take the melatonin, perhaps splitting the dose? With your pdoc's okay, of course, perhaps you could take one pill when you go to bed and then take the second one when you get up to use the bathroom. That would help extend the time that the melatonin would be effective and may give you that extra hour you need. If you have trouble falling asleep, you could try other techniques like aromatherapy or a white noise/sound machine to help make up for the loss of a melatonin pill early on.