@Gaining-clarity - I'm going to go at this a different way from
@Friday. Let me qualify first - I have read what you wrote a few times now and am seeing a lot more between the lines than what I'm seeing typed because I have and still am working through this desire/drive to become engaged with others as I, too, have been/am very lonesome, and have looked outward instead of inward to fill the void and for definition with negative results. I wasn't ready and didn't know what "boundaries" were, so it left me dangerously vulnerable and I was harmed/taken advantage of. That's my story, though, and your relationships and experiences could be totally different. If that is the case, forgive my projecting and consequent observations. It's just that a lot of what you've shared resonates with that part of me. I'm going at it cautiously though, so bear with me.
First, I would ask you, "What is motivating your desire to share your struggles with others?" I'm asking because I see a lot of what I used to think and feel in what you've written. I would offer that it might be wise to know your intellectual and emotional mind, and to guard your heart before moving forward.
What you've written that gives me pause is copied below.
" I'm terrified of exposing my feelings and being so vulnerable. If I shared, I'd be in need of such reassurance it might frighten someone."
"I think I also feel ashamed of "how" am, meaning I think I'm very immature in many ways and I don't want people to know this. I also don't want people to know how much of my life is affected by trauma. How it is so real on a daily down to every detail of the day basis. There's so much I don't want people to know."
"I hide so much of my struggles. I have a lot invested in seeming as though I have it all together. The ONLY reason I can seem this way, is because I stay pretty far away from people. But I don't like feeling alone anymore."
What I'm seeing, and correct me if I'm wrong, is that you are ruled by fear that presents itself as vulnerability (fear of exposure and fear of being needy and reliant?), shame and a consequent need to hide to protect yourself from judgment/reprisal, and the feeling that you're not quite "normal" because of what you have going on. Thus, you feel a need to keep up a front and the question remains: "How do you do so while also sharing about such personal and deep-seated issues?" This is where Friday's suggestion regarding looking at your thinking would be very helpful. Really nail down your core beliefs, thought patterns, and motivations, first, before moving forward in letting others into your world..
If one or any of these apply, or even in taking your response as a whole - it seems to me, from my vantage point, it might be more helpful and healthier for you if you started by building a relationship with yourself. That you become your own best friend, your own advocate and cheerleader, and that you examine your thinking, and learn to strengthen and fine-tune your ability to rely upon your intuition (the still, small voice inside). @Ms. Spock's threads on mindfulness and self compassion might be helpful in this area.
One last point regarding intention - If you find that you are reaching out to others to fill a void within yourself or your life, or for acceptance and validation, I would suggest that you take stock of where you are at within yourself first.
Just some thoughts from one who has been and is still moving through that portion of self re-architecting. I hope I haven't muddied your mental waters, but wanted to offer up a few points for you to consider if they apply. Best to you. VB