As one who has smoked cannabis most of my adult life (I'm now 55 and very successful, so there go the lazy stoner arguments) allow me to offer some suggestions to new consumers. First and foremost, just relax and go very slow to start. Whether you're smoking, vaping, or using edibles or oils, the amount to 'do the job' will vary from person to person, so always start with the smallest dose or no more than two puffs. Remember, no one has ever died from a cannabis overdose and you'd have to ingest about a semi-trucks worth before reaching lethal levels. Even if you pass out, cannabis does not inhibit your bodies ability to continue breathing or for your heart to keep beating like opiates can. Yes, today's cannabis is more powerful than what your grandma smoked at Woodstock, but that just means you need to use less. You may think you're going to die and may start to have an anxiety attack, but you'll be okay.
The reason I think most newbies start to have anxiety attacks are pretty obvious if you think about it. Many people still view cannabis as something bad or evil or illegal, so they're already putting themselves in a paranoid mindset. To me, cannabis IS medicine! If you're using this for pain relief you should feel no more quilt than you would when taking an aspirin or injecting yourself with Humira. Get over that right now! There is legitimate science backing this up and forget the fear mongering of the politicians and moralizers.
The bodily sensations you'll begin to feel as the medicine takes effect can be very disconcerting for many. You'll begin to notice things going on that you never picked up on before. You may become more aware of your heart rate, your breathing, notice sounds that were always there but you had tuned out before. Don't allow yourself to get into a negative feedback loop just because you're noticing some of these things now that you're more aware. Allow the medicine to show you what you need to work on. If you feel anxious it's probably because you were already anxious and the cannabis is pointing this problem out. God, that really sounds like something a hippie would say, but it's true.
If you still feel anxious/panicky, drink a glass of water and go outside for a walk to get your mind out of its self. Enjoy nature and stop focusing on what your body is feeling, it will pass. I've also heard that chewing 3-4 black peppercorns will help, but that may just be an old folk tale.
Finally, does cannabis really work? That's like asking if Humira really works. Some swear by it, some swear at it. For me personally, I can't say that the pain entirely goes away, but it just doesn't seem to bother me as much after smoking. If I'm smoking and consciously think of what might be hurting... then yes, I'm aware that I still hurt. But what it does for me is it lets me get my mind off of the pain and it actually does allow my neck and shoulder muscles to relax. I have a lot of pain in my neck and shoulders from not just bone fusion but also from fighting to maintain my posture as straight as I possibly can.
I'd definitely suggest anyone give it a try (if you can legally get it of course ;)) and see if it works for you. Even if it doesn't help the pain it's 100 times safer than alcohol and doesn't give you a hangover. Nothing wrong with laughing and enjoying everything at a higher intensity than before.