I suggest you seek out a pain management specialist first and attempt to get a definitive diagnosis. This may be difficult for you because you are only a few months post op after a fusion. A fusion would be expected to take a year or more to settle so its odd that your surgeon has washed his hands of you so fast. Someone else may be reluctant to do much including committing to a diagnosis except issue pain medication when you are so close to the date of your surgery.

It is always possible that there is pressure, scar tissue or post surgical rubbish in the area of the fusion which is pressing on nerves and causing these problems. It may be CRPS but these sorts of symptoms can equally be caused by pressure or irritation arising from a mechanical issue in your back. In that case it may be that there is something that can be done to reduce or remove the symptoms you have. Sadly, the only thing that back surgery is virtually never recommended for is reduction in pain - it will fix mechanical problems but is notoriously poor at reducing pain. You need to ensure that things are ok where your back surgery is concerned and I am surprised you have been discharged so rapidly. CRPS is a diagnosis that can only be made once all other more likely causes of the pain etc have been ruled out so it is important to find someone experienced to make sure that any other cause isn't missed given your recent surgery.

You need to find a pain management specialist who has familiarity with CRPS and not get too caught up in what you are reading on the Internet. The people who make good recoveries don't usually bother to post their experiences! I can't lie, it's a horrible diagnosis to have but wait and see what the outcome is before you get too caught up in the horror of it all.

You said you were worried about just masking the pain. People worry about this a lot. Unless there is a mechanical cause for your symptoms which can be relieved by surgery or PT for example, the best you can ever hope for with chronic pain is to mask the symptoms. For some people, the pain gradually goes away over time but medical science has no means of curing CRPS and most other chronic pain problems. Trust me, the drugs and most other interventions aren't actually that good at masking the pain. If they were, we wouldn't be posting on here! You are likely to still feel quite enough pain to know what is going on even with effective pain management.

I'm sorry your situation is complicated and difficult for you but I hope you find someone who can give you a better idea of what is going on soon.