Well, that was a fucked up night. Thanks to my bitch ex girlfriend for setting the ball in motion about me getting paranoid, thanks to my dumb ass for wanting more and more, and thanks to the hospital for the Ativans. What a trip...
Professortweak we've all been there man so use it as a learning curve for the future. Although you felt good coming up somewhere along the line something clearly peaked your anxiety and you mentioned pupil size so you looked in a mirror I bet it only freaked you more.
It doesnt take much time to spiral out of control either once something unfamiliar happens or a feeling we havent felt before in our body goes off. Its in first stages you have two options embrace it or fear it in my experience. Ive done both and fear only creates anxiety which speeds your body and mind up even more which is unpleasant and you feel you're powerless to stop things even more.
Example 1st you may feel like somethings wrong then that sends signals through the body you start to worry about what it could be. You havent any clue its all new and welcome.....FEAR OF THE UNKNOWN... You tell someone you dont feel good most the time they google shit which gives 55 things that maybe causing the way you feel which only again adds to the clusterfuck in your head. It may start from a noise or paranoia either way FEAR OF THE UNKNOWN its all in your head.
In regards to the visual and auditory hallucinations over stimulated...Next time remember you're high as fuck and don't fear them. Laugh have fun with it all just ride the wave next time brother stay calm no matter whats thrown your way find a way to enjoy it. Easier said than done i know it takes practice but every time ive lost my shit and worried i may die right after the shot or just been paranoid as fuck its landed me in a hospital but im still alive and every time ive freaked out its been over nothing a few times i swore i was having a heart attack for instance get to hospital find out hearts going just fine... its been years since i felt like you did but it was common for me to freak out regularly as a youngster on meth. You know that hospital means you are safe too if something is wrong so your anxiety starts to leave pretty quickly in there.
My advice if it happens again is dont worry laugh it off or distract yourself whatever you do don't feed it. You can calm yourself with breathing techniques at anytime. Sit down put your elbows on your knees lean forward deep breathes that position is going to naturally slow your heart rate down breathing deep but steady helps with oxygen. You can also put a cold washer on the top part of your neck over certain viens Google it man. Last is pills 10 or 15 mg of Valium will slow you down reasonably quick as im sure you know already.
The shaking in your hands is central nervous system related from what i have read and been told if its long term then see a dr.
If it only happens when you inject its something ive seen many times in pretty inexperienced iv users. As soon as the blood hits they shake like leaves or people with issues hitting viens are the same. Again relax take your time dude.
You mentioned blowing out viens and missing shots. Ill be honest your technique maybe the issue because to me it sounds like you're relatively new to the steel. I say this due to the questions you've asked also. If you are new you need to fucking relax before anything else. If you are using a torniquet release it after registering and before you inject. It doesn't have to be all that tight if it is you will find you may cut the blood flow too much making it impossible to register at times.
Use your arms if they are still good before anywhere else in the crook of your elbow you should have 3 viens easily accessible always go up the river which means shoot infront or above your last hit saves your viens. If your arms are gone in the crook go toward your hand and find the same viens and if they're mia... Hands are next but be gentle and inject slowly and you'll be fine.
I also suggest to inject slower than you seem to be as the slower you go the more calm you'll be. The faster you inject the more chance of blowing a vein because its under more pressure than it can take. The rule is the smaller it is the slower you go. If you go slower you have more control and should be checking half way down you're still in the vein. Slow and steady wins the race. Fresh rigs help with vein longevity too. Rotaion use a different vein each time if you can even if its only two you rotate better than none... When you register too let the needle sit flat against your arm if possible... Stops you having to focus on supporting so much and will be easier to shoot.
Lastly symptoms of an od arent pretty Ive bit the dust a few times and have been lucky.. You lose your vision and hearing and shake like a mother fucker all the while your heart is beating eraticly and you are gasping for breath if your oding you will know because its instant and will scare you or kill you. There's no real indicator as to how much is too much before its in you and its too late. You said you were inside on a vacation so id say your tolerance is non existent to low right now just take it slow be safe crawl then walk. You seem like you pushed it pretty fucking far and as a result look at where you ended up bro. Use the other day as a guide to what you could handle and go from there.
If you're using powder and not crystal its usually less forgiving on veins and the kidneys due to it having as high as 10 times the amount of chemicals and shit in it than crystal. It results in a dirtier less pure cheaper product. So filter it vigilantly.
Sorry for the post length man and hope its helpful stay safe...