I'm not going to say whether or not you should take morphine, but rather address the broader issue of chronic pain for someone of your age.
I'm in my mid-40's and my pain issues started in my mid-30's. For about six months, I said no to any opioids, hoping that the pain would go away. It didn't. I then only accepted the weakest options (darvocet, tramadol). Another six months in, I finally turned to hydrocodone.
Along the way, I had various treatments (PT, injections, and eventually some surgeries). I also tried NSAIDS, TENS, etc..
So, nearly a year in (like you) I came to realize I needed something to help me -- so I didn't have to spend most of my time in bed, so I could go out for a meal, so I could focus on work, etc..
The meds have allowed me to do all that, but it is now a daily battle between how much pain to tolerate vs. how many meds to use, fully aware that the more I use, the more tolerant I become, the more dependent, and the sooner I'll have to ask my PM for a refill (which always scares me). So, moving on to opioids may help relieve the pain, but generated a bundle of new issues.
At just 18, those issues will be even greater for you: more years ahead, and more potential suspicion from doctors. I don't know whether there are surgical options or other treatments, but if you can find a way to be without pain through them, they would be far superior to a life of opioid use.
Only once all else has been tried and failed, especially at your age with possibly 60 years of opioid use ahead, should you accept that fate. Just consider how in the world will you be able to keep the meds effective for so long?
Hope this offers a helpful perspective.
C4-T4 Scoliosis (disk degeneration, stenosis, narrowed neuroforamen, bone spurs), RT hip and SI joint damage from car accident. Also, pectus excavatum, supraventricular tacycardia and mitral valve prolapse syndrome.
Current meds: Ultram ER 300mg daily, breakthrough - hydrocodone 10-15mg, or oxycodone 5-7.5mg. .25-.5mg ativan as needed for sleep, Verapamil 240mg SR (for tachycardia). [/gray