#1
Okay so about 8 months ago when I started singing I had terrible technique. I'm not even sure if you could call it technique: singing from my throat, shouting to reach high notes, making myself hoarse for a day etc. I probably did this for about a week or two until I realized it was terrible.

I'm worried that could have had a lasting impact on my cords. I don't go hoarse nowadays, but whenever I really struggle with something I think it might be nodules. I'm a really paranoid person to the point of sickness so if someone could tell me the tell tale signs of nodes I'd really appreciate it before I see an ENT doctor.
#2
Don't think you caused any damage within a couple of weeks. Nodules form over time, think of them as calluses over your vocal cords caused by windburn.
#3
I agree, I'm sure you have no long term damage at all. You'd need to sing badly for way longer than that.

Quick tip I got from a vocal coach once:

Practice with your hand on your belly and before singing breathe in to make yourself feel as fat as you can. Then as you sing a line, feel the air draining out from as low down in your abdominals as possible til you feel as skinny as you can by the time you next need to breathe.

Everyone gets uptight about "chest up, chin up" etc to project, but its way more important to feel the singing coming from your deep in your lungs and not your chest or throat.

Keep it up.
#4
^ I agree with the first part... "Practice with your hand on your belly and before singing breathe in to make yourself feel as fat as you can. Then as you sing a line, feel the air draining out from as low down in your abdominals as possible..."

... but not the second part...."til you feel as skinny as you can by the time you next need to breathe."

You want to sing, as Lamperti said, "as if continuing to hold the air in the lungs." That means trying to let out as little air as possible. By the end of the phrase, you should still have lots of air left if you are singing correctly. If you feel "skinny" by the end, then you are using too much air.

The consequence of singing with poor technique is damaging your voice, and the following list is pretty daunting:

https://www.ultimate-guitar.com/forum/showthread.php?p=22022422#post22022422

CT
Could I get some more talent in the monitors, please?

I know it sounds crazy, but try to learn to inhale your voice. www.thebelcantotechnique.com

Chris is the king of relating music things to other objects in real life.