Depends on how far along the journey is...
The following is written for a support person, and the person going through the surgery so adapt as necessary.
Someone to listen; and if possible connect someone with lived experience of that surgery.
It's also worth highlighting that incredible pain does really weird things to the human brain and may cause unexpected behaviours. Absolutely keep on top of pain meds, even if pain isn't currently being experienced - surgical pain does return very quickly when pain killers wear off, and can have a lag time before analgesia kicks in again - meaning you're along for the ride on the pain train until the meds apply the brakes.
On that basis: don't ever discount professional psychological support. I have been downvoted for this before, though professional psychological support is just as essential as surgical care pre- and post-op. It is important to be able to vent to a person whose job is to have your best interests at the forefront, who is completely independent of others in your life, to offer guidance, support, and counselling.
I still strongly argue that psychological support should be mandatory because of how complex we, as a group of people, are. I get accused of gatekeeping because of this, though I know countless people (gender diverse and not) who have been able to properly help themselves because they kept seeing a counsellor/psychologist. Our minds are incredibly powerful organs - it makes sense to keep them regularly serviced too, just like your car's engine.
Nurses do get busy and sometimes things do get forgotten. It is very, very easy to become resentful though it's important to remember that none of it is personal - most nurses are incredible human beings. Just keep assertively, but kindly, advocating. 'Please' and 'Thank you' are incredibly powerful phrases. People are more likely to willing help people who are kind to them, it's just human nature.
Don't be embarrassed or precious. If something feels wrong, off, or painful - ask. It's better to address a little problem quickly, rather than let it spiral out into a huge problem that takes a long time, or more surgery, just because one was too embarrassed to ask.
There can be unexpected sources of pain - ironically not from the surgery itself: the catheter can cause uncomfortable pain once the bladder 'wakes up' after a few days. Apparently a catheterised bladder will enter a catatonic state for a while, so my surgeon said, and when the bladder does wake up it can lead to stabbing like pains for a while. This can be problematic whilst the catheter must remain in place as everything heals. A strong oral pain killer usually does the trick though.
Toileting/hygiene
Some of the pain medication is opioid-based (organic or synthetic, it doesn't matter), which means constipation will occur. Consult the surgeon and care team for advice, though try to cram as much fibre in as possible. Stool softeners may be recommended. The first bowel movement after surgery (which could be days after...) will be difficult and possibly painful. It is vitally important not to 'push' or 'strain' as that can result in injury and a possible emergency trip to the operating theatre.
Shower after each trip to the toilet to ensure the surgical site is kept clean. Nurses should be able to help and check that everything is clean. Keeping the surgical site clean is vital to prevent infection, which can lead to horrible or even life-threatening outcomes (sepsis is not to be fucked with).
Medical procedures
Wound separation (stitches breaking) does happen, and can look catastrophic, but it is important to remember not to panic or get upset.
It will heal, surprisingly even large separations will close themselves eventually (with the right care) and it will eventually look normal.
Be sure to involve the surgeon and care team if it happens, it will be okay. It happened to me, it was horrific looking but has completely healed over and isn't even really noticeable.
One last thing on 'looks' and illusions/'Instagram' expectations: don't get hung up on them. Vulvas and vaginas come in many millions of shapes, sizes, and colours (even multiple colours).
What might look catastrophic or horrific now, won't be what it looks like after healing has completed - which might take up to several years. Healing doesn't just include stopping bleeding, and closing wounds. Healing also includes skin resurfacing and reshaping as swelling dissipates, which takes a long time to properly settle. Swelling for me took a good 18-24 months to properly dissipate.
Be patient. Don't get upset after six months because 'it doesn't look right'. No one 'looks right'.