I had a big problem with sleep hygiene as well since I often would turn in early at night to rest when I lived with others in order to be in a quiet space where I will likely not be disturbed until morning. I found that I had to set some rules for myself if I wasn’t feeling tired enough to fall asleep. My rules were: 1) do not go under the covers, 2) since i hate wearing socks to sleep I made sure to keep them on until I was ready to get under the covers, 3) make sure I feel relaxed. I often have to have a hot shower before bed to raise my body temperature before I get into bed because the feeling of my body temp dropping makes me sleepy.
As for the tolerance issue, I would say that there’s a lot of factors in finding success for it. Someone else in the comments said that you have to change. I think maybe there’s some skills for you to work on, but fundamentally I don’t believe you need to change. I think that I can sense a feeling that your friend and former girlfriend didn’t seem to respect what you were requesting of them. I can understand how that can be a tough subject to tackle, especially when you’re actively overwhelmed. With the people I care about, I have discussed with them that there will be times where I can’t really speak or be spoken to and that I’ll give them a signal/codeword so they understand when I am in that state. I bring some earplugs with my everywhere to help against overstimulation since I am particularly sensitive to sounds. Most people seem to respect when I request some quiet. I often will discuss with them after the overwhelming feelings pass about why I got overwhelmed, if I know why, so that if it was something that they did that we can talk about how to avoid that going forward. Though I do believe that this makes me hard to be around as it makes others feel like they walk on eggshells around me, at times.
I believe that there’s a few things that you should talk over with your therapist about. The first thing that I found helped me a lot was getting better at recognising my limits. I know it night not be the case for you, but for me I really struggled to recognise getting overwhelmed until it was too late and I was melting down. This skill is necessary for the second thing to consider. The second thing to talk about would be gaining some more effective communication skills. Of course, it takes two to have a conversation, but doing your best to convey your thoughts, feelings, and intentions is important.
Let me know what you think. I hope something in my comment helps!
Someone I know got banned for saying “anyone can be a shithead-- transpeople aren’t exempt,” on a post about a transperson who sexually assaulted a minor.