I don't think you rambled.

Try not to completely freak out about this. The hard thing with lithium is that normal and toxic look a lot alike. That's why they test your blood so much at first (and later at least every 6 months if not more often). Hand tremors are normal; I had to take medication to control them. GI issues are normal, especially early on. Cognition can be weird at first. There is such a small difference between normal level and toxic level that side effects look the same.

However, I think you need to get a level done soon, like as in tomorrow soon. You are not on very much at 600 mg so toxicity is not very likely. But anytime you are not feeling right on lithium you need to get checked. Some people are more sensitive and can be bothered with a lower level and some people have a lot of toxicity symptoms at lower levels. Please call your psychiatrist in the morning and explain that you have not been feeling well on lithium and would like to have a level drawn. Make sure you tell them everything you said above,including the difficulty with writing papers. They should respond to that with an "OK" and hopefully questions about how you are feeling and they should tell your dr. all of this. If they argue with you wait until you are close to 12 hours out from your last dose and go to urgent care and request a level. And then find a new psychiatrist because they should always agree to give you a level if you feel you need it (unless they have a good reason to say no of course but my experience was that if I wanted a level I got one). And because they should have explained this to you already.

Here's a non-scary article on lithium and toxicity (a lot of them are unnecessarily scary):
Lithium Toxicity

Lithium is definitely something you have to learn to handle and observe and not push through. My 6 months of my first toxicity was excusable medically like I said but I also was insisting that I was fine and just stressed and not focusing on getting the labs with a full 4 days of lithium in me. I threw up so much during that time I had to have my entire front tooth surface replaced by huge fillings because I damaged my teeth vomiting. I was living on Coke, water, crackers and Dumdum pops for dry mouth. It was really not good and I was trying to do way too much (my therapist moved with almost no warning so I had to change rapidly and then my assistant was fired 2 weeks later. They had been trying to hire a 2nd assistant for me and so I wound up essentially doing 3 jobs. I kept telling them I could only do it so long and that I couldn't keep working 60 hours per week much longer and they ignored me until I wound up disability for 4 months. I'd been more or less off meds for 2 months by then because of all the vomiting. My therapist actually noticed it. He happened to walk behind me to his office and saw I was dragging one leg slightly and then I was slurring my speech quite a bit so he called my psychiatrist and she had me do anything I had to in order to keep things down until a level was drawn and then called me with "I know why you've been so sick!!!".

The more severe things I've never noticed on my own; I've noticed after the fact or felt there was no warning at all. I tend to think that is typical and that the things you are aware of are probably adjustment that is really hard on you, harder than it should be, but you can't know without a level. How long have you been on it and how long since you had a level drawn?