One Flew Over the Cuckoo's Nest

Last night something happened. Our life, as we have known it, changed. Tristan took a leap and the crib has been rendered useless! He climbed out for the first time ever. I was hoping he would not figure this out and we would be able to keep him in longer. But, our little boy is growing and I cannot stop him.
Why is this such a problem, you might ask. . .let me explain what happened when Kennedy figured out how to climb out of the crib. At first it was kind of cute but then she started coming into our room very early in the morning. Instead of getting up with her or taking her back to bed, like I should have, I tucked her safely into our covers and sometimes she would fall back to sleep. I didn't really mind this until she started coming into our room in the middle of the night, sometimes we would have multiple visits before morning. Then we moved her to her big girl bed and I couldn't keep her in that either. It was a constant battle trying to get her to sleep there. She would come out of her room, I would take her back, come out, take back, over and over until one of us would give in. Her sleeping patterns completely changed and sometimes I would resort to resting beside her until she finally fell asleep. Then Tristan came. . . .that just complicated the situation even more, but luckily the battle didn't last much longer.
Now I have Tristan who is all of a sudden terrified of the dark room that is his at night. He cries for "Mama" and climbs out at will. His usual bedtime is 7:30 and last night it was 9:30 until he finally let himself fall asleep. He greeted us at our bedside at 6 a.m. carrying his blankie. Too tired to take him back to bed and start a battle, I let him in ours. I am hoping that we can work out some sort of "routine" or figure out what works for him before this baby comes in five weeks. I don't want to be getting up with two babies again! One is enough for me, thanks.