1) You are not invincible, but is it too hard to concieve that your anxiety, and associated physical stress response could be exasperating the issue? Confidence in the movement is a must, I stop an excersise the moment I start feeling that 'ugh, this feels like it MIGHT go bad.' Some people may call me a pussy, but this kind of training, where you aim to minimise your stress response and anxiety has made me very strong.
2) Not so much a matter of slowly, but at a rate where you do not feel anxious approaching a weight or a movement. At the end of the day, who gives a fuck if you move a weight from point A to point B in a predefined movement pattern? It's inconsequential.
3) I hate the tough love approach, but seriously dude, stop being a bitch. The thing you need to remember is that NO one is forcing you to lift. There is a HUGE difference between wanting to lift, and having to lift. You don't HAVE to do a single fucking thing, everything you do is because you want to.
If balance is good, and training is sensible with technique, imo injuries will develop purely as a response to how stressed out you are about training. If you are constantly having to force yourself to do something, the body will find a way of stopping you stop the incessant tide of anxiety and cortisol. Learn to live within the perfection of each rep. And I don't mean perfect in the bodybuilding set, but perfect in that each rep is something meaningful, powerful and enjoyable. Like I said, whenever things start turning ugly, eg slow ugly grinding sets, pain, anxiety, I cut the excersise right there.
Next time you train and are feeling these feelings, take a breath, stop and do two things.
First, remind yourself that you don't have to do a fucking thing if you don't want to.
Second, ask yourself if you want to do this or not. If you don't, then THERE IS NO ISSUE. Once you realise that, training can again become enjoyable.