@MissGremlin
You're definitely not a lost cause and most definitely worth helping. You've just been through, and going through a lot of really difficult things in your life. And that is just unfortunately beyond the skillset for a lot of people to handle.
I've never worked on a crisis help line or done much training. I've done a little bit, but even before i did that my answer here would be the same. If it was me talking to you and i didn't have any more ideas of how to help... which is so often the case... i'd just ask if you'd like to talk about it, and just be there to listen.
You would know far better than me, but that seems like a reasonable step to take. Sometime all we can do is just listen and be there for someone. The fact you told them the triggers with smell and taste, but they wanted you to do it anyway just seems to me to indicate they failed at the first hurdle and weren't listening to what you said. How can they help in any way if they don't listen?!
I get the same thing with people telling me about grounding exercises and meditation/mindfulness. It just doesn't work for me. If i'm spending all my time trying to keep my mind distracted... to avoid silence and doing nothing, because that's when the anxiety and depression starts to take hold... sitting there quietly while doing nothing doesn't help me at all. I need to be doing something! But it works for people and if you reject their advice for any reason then they see it as you're ignoring them. Which is ironic, as they're ignoring what you're trying to tell them. My current psychologist listens to me and tried to understand and we work within that. She's been helpful so far in my first 2 session with her. The fact those 2 sessions have gone for almost 4 hours in total doesn't hurt 😁 But its not cheap, even with the refund for the MHCP. I used a free oncology psychology service before, last year as you may recall... you definitely get what you pay for.
I've found someone who helps me, listens to me and validates my feelings and experiences. She listens and offers advice based on what we've discussed. At no point has she dismissed me or made me feel wrong for not taking any advice she's offered. Does this mean i was a bad person before or not worth helping before? Of course not! The person doing the helping was just woefully inexperienced with my particular situation.
You've said the chats and support here help you, so it proves you are worth helping and can be helped... you just need to find people who can, or will, do it. I'm not sure these crisis lines with getting to speak to random people is that helpful for you. But there's so little choice when seeing someone professionally can be so expensive. Prohibitively so for so many people.
But you're not a lost cause. If anything, a cause very much worth taking up. Don't let anyone make you think otherwise. And s#&%w them for making you feel like that! It's the system that's broken, not you. I know that doesn't help you much, but I feel like it's important to keep in mind.