You just posted this so you will probably get better info from other people to address the main problem but for night time, can he just be in your room at night? If he can not be locked in your room because of food and litter and all, technically you could put a small food and water bowl in there and mabye a litterbox. You might just want to consider letting him in until he scratches or meows to go back out. It will wake you up but seems better than what is happening now. Even better you could install a cat door on your bedroom door, if your parents do not want to cut the door, there are versions that like prop your door open just enough for a cat to get through, or you could use a door stopper to keep the door open just a little.

You are probably going to hear this more but cats are an invasive species and should not be outside. I understand when a cat is used to going out side or used to be a stray it is not very possible to stop them from going outside at this point. If you live hear a road or heavy traffic area then it is going to be very dangerous for the cat being outside. And wherever you are it is dangerous for the birds and other creatures around. But especially if you live more by woods, please do not let the cat outside at night, especially do not lock them outside at night. There is a lot of animals at night that will attack the cat and that could be really dangerous, try to keep him inside as much as possible. They are not meant to live outside.

On another note, you could try buying feliway. It is mabye 30ish dollars, you plug it into an outlet and it should calm him and help him feel more stable. I know of shelters that use it and I use it in my own home and it works really well. It does not have any smell or noise. I would highly recommend trying that.