I am very glad you wrote. It is a sign that you want to make your life better. It’s a good first step. Now for the next steps.
First, you really have to stop smoking weed. Yes, it helps you feel better but it also depletes your motivation to help yourself. And you need all the help from you you can get.
As you have already discovered, sitting in your room by yourself and feeling bad isn’t helping you a bit. The solution, as difficult as it may sound, is to get out of your room and do something, anything, that is productive and with healthy people. Instead of isolating, find someplace in your community that needs help and offer to volunteer.
Being a cleaner probably isn’t the answer, unless it is with a fun group. Instead, find a senior program or a program with kids or a charitable organization that can use some help. It doesn’t have to be complicated. Sometimes such programs just need help sorting stuff or help with clerical work or a fundraising campaign.
The advantage of volunteer work is that it puts you in regular contact with other people who share an interest. There is no pressure to be an instant friend. Everyone is there to get a job done. Friendships develop gradually and organically.
I do think you need some therapy to help you deal with your guilt and with trauma from sexual encounters like the one with your uncle. The treatment of choice in the U.S. for Borderline Personality Disorder is Dialectical Behavior Therapy (DBT). See if there is something like it in your country. You can also research it online. If DBT isn’t available in the Netherlands, get a referral from your doctor to a therapist who specializes in personality disorders and trauma.
You need and deserve therapy to help you make a new start in your emotional life. You are only 19 with the potential for a long and productive life ahead. Take care of yourself — please. Get the therapy you need. You are worth it.
I wish you well.