When it comes to depression, there are some things you can do on your own without meds or therapy (I would still recommend both). Part of dealing with depression is dealing with the way it tells you nothing will work and to give up and to not keep trying, it can be a very insidious enemy. Anyway, do what you can to keep eating regular meals at regular times, stay hydrated, keep a regular sleep schedule with enough hours of sleep and do what you can to go to sleep on time and wake up at the same time every day, keep doing those things you love like Lego, go outside and walk in green spaces for like 30 minutes every day, keep reaching out to trusted friends do what you can to keep yourself continuing to reaching out. Some or most of these may sound impossible, some or most may sound like they won't help - they might not take you all the way but they can help and part of why it seems like it might not or isn't working fast enough to keep it up is depression telling you it won't. You should still seek a psychiatrist and/or a therapist to really help out but these are some things you can start right now. There's a lot on that list, if it seems overwhelming start with one (I recommend keeping a regular sleep schedule or keeping fed at regular times or if you're particularly ambitious getting 30 minutes a day in a green park or out doors). Then keep adding when you can.

For you, you have made some very good active steps in your life. You're looking into diy or actually ordered some. I think you mentioned being out to a friend or friend(s). You're planning for the future when you can be away from your parents. These are all good things. You can make progress. Just stay alive, things will get better.