What the hell am I doing?

So. I’m Needles (well, that’s the English translation of my surname, anyway).
Hi.
Straight up, I am not a simple OCD case. I have a complex and severe disorder which has uncontrollable compulsive behaviours and urges attached. But OCD folk may be able to relate somewhat.
I wondered if anyone has a clear correlation between A and B with OCD. For example stress = behaviour A triggering in order to provide calming effect, or similar. Do you know why you enact your behaviours? Is it as simple as you’re anxious and therefore you enact a behaviour to comfort yourself?
Because for me, this seems completely random, and therefore, utterly unpredictable and unmanageable.
I’ve been having a really bad time with acting out, so I decided to do a bit of a progress day : Record a couple little videos for myself about what I was doing, where I was going, what symptoms were happening, when they triggered off and when they didn’t, and how I was feeling (eg stressed, angry, whatever) to try and work this out so I can deal with it better.
Perfectly reasonable. But it ended with me "taking too much of" (and really? You're not ALLOWED to type the actual word when you have a mental health condition???) (at night, in a graveyard – oh the irony) on a substance the compulsions have started demanding and helplessly enacting a lot of my worst behaviours. Then I had to go back to where I’m staying and, as always, try to pretend I am fine and normal when I’d just spent an hour throwing up, had dizziness/blurred vision/pain/nausea and was busy watching how bad the "poisoning" (and again, censoring the actual word for the experience?) was to determine if I need to go to ER. I’d spent the whole day enacting an obvious external behaviour which I find very embarrassing.
I’d emailed the therapist the day before, with no response.
I have tried SSRIs of various kinds, anti-psychotics and other medications recommended for OCD, behavioural therapy, and am currently trying exposure therapy. NONE of this makes the slightest bit of difference to my illness.
It’s chaos – I can be in the same place, feeling generally the same way, and I will either act out badly or be (outwardly) normal. I can feel fine and compulsions will hit hard, or I feel fine and they don’t. Same as when I’m stressed or whatever else. There is no pattern. I cannot anticipate and therefore avoid triggers. There’s nothing I can do.
I do not enjoy my behaviours. In fact I find them very distressing. They don’t provide me with comfort, calm, order, or focus. They screw me. I wish more than anything I could stop but I’m unable. They’ve been dangerous for some time – There have been substance abuses in the past, that I had tried to “self medicate” with and push the issue down, but I had thought I recovered from that six years ago. Now this. I’m shaking which is not in itself serious, but I’ve essentially been poisoned by my own illness, and it may escalate.
How do people with OCD manage if there is no pattern? Does OCD itself dictate a pattern?
Are your behaviours, maladaptive as they are, always for a reason?
I don’t know why I act out the behaviours, other than there is a compulsion that I do so, and I have no choice in the moment. That’s it. I wondered if there could be something like Tourettes Syndrome involved, as the compulsive feeling must be answered by the behaviour. Is this common in OCD? What does it feel like when you are forced to act out?
Impressions welcome.