Normal to have severe stiffness/pain3 wks postop from lumbar fusion?

I had ALIF surgery a week ago tomorrow. On L4-L5. I had no disc in between the vertebrae, and L4 was slipped over L5, so it was bone-on-bone. Very painful which I was managing with ice paks day and night and 2 hydrocodone per day for quite some time. So I was a candidate for the ALIF. I was basically a 'clean slate' for this surgery, meaning I had no previous abdominal surgery (including pregnancy), no diabetes, no blood thinners, not morbidly obese, etc. The only thing was my lumbar spine had a 90 degree angle which made it trickier. The docs said they'd never seen a spine that deformed. So on with the procedure: it was one day, not two. About 5 hours or so. I came through fine, no complications. Sore? You bet, but soreness from the surgery incisions on the front and the 3 on the back. When they go in through the front, they make an incision from below the navel to the pubic area. And they have to move a lot of 'stuff' in that area to access the spine in order to put the spacer in. That's why it's so sore in the front. And puffy, from all the tissue trauma---to be expected. Yay for ice packs!! Keep 'em coming! And oxycodone, plus other meds. In the back, tissue trauma as well, but again, yay for ice packs. The agony of pre-surgery pain was gone, so I had no fear of the 'lightening bolts' of pain due to the slipped vertebrae. I am being very conservative with use of oxy---only 2 per day. Plus x-strength tylenol (no advil, sadly). But it will take, from what I have read here and other spots, several months for everything to knit together regarding the hardware that holds the 2 vertebrae til they actually join. No BLT's: no bending, lifting, twisting for months to come. I sleep in an adjustable power recliner which helps me get up safely--I highly recommend this, even if it is expensive---it is a worthwhile investment ( we actually bought it for my husband after his open heart surgery several years ago) and could save you from a movement accident. Also get one of those toilet seat risers.
Now, 2 weeks post-surgery, am I glad I took the chance? Yes. Do I have pain? Yes. But it is bearable, and I know that given plenty of time, the pain will subside. There is a lot of tissue/abdomen disruption with this surgery, so pain is to be expected but can be managed. providing you have enough flexible ice packs for both front and lower back, pain meds, plus people to help with basic needs. If I had not had this surgery, I would have been 'living' with unbearable, excruciating pain from those vertebrae pressing on my spinal cord, which oftentimes drove me to tears---and I am a pretty tough old gal. This is a very long answer to some of your questions and concerns, but hopefully will help you. Best of luck. PS one last piece of advice: choose your surgeons wisely!!!