Hello Phoebe! 
How wonderful that you are doing well!! It all sounds quite normal, if that gives you any comfort. Just stay on top of your pain meds. Keep a schedule on a pad of paper and write down everything you take and when you take it so there is no confusion (or fear of overdosing). I tried to make sure I had pain meds on board when I typically had to use the bathroom. I usually go after meals, for example. So I tried to time the doses so they would be in full effect. I never let the pain meds lapse! But I am really really a chicken about pain. I found I didn't really have much pain at all -- really -- after about the 3rd or 4th day. I also learned how to get out of bed (roll off -- don't sit up), how to lay in bed, etc. 
And welcome to the seton club!! 
A rare bunch we are too! My doctor calls them body art or unusal body piercing. Yes, extreme body piercing and not for the faint of heart! I've had red, white, and blue ones. I think the color indicates the thickness, but I am just guessing. My current two are a very fashionable red!
My largest abscess (actually twin abscesses -- both large and very deep) left me with a wound hole the size of a small ice cream scoop. While I love my surgeon, he didn't warn me about it. I was alone at the time and had a friend bring me home right after the surgery. The friend didn't stay because I said "I'll be fine". Well, I had to pee, so out comes the bandages and I had to look with a mirror -- and I nearly fainted when I saw the large, deep whole! I felt woozy and went down on my knees and held on to the toilet to steady myself. 
I thought how can I handle that?! How can you even go to the bathroom and clean it!! I was petrified. I didn't have a hand-held shower sprayer yet. I am so glad you have your sister with you!! For emotional support if nothing else!
I asked my doctor about the cleaning. How can it not get infected with poop and pee down there??? He said to work hard to keep it clean but understand that the body is used to dealing with poop and pee down there. Pee is usually sterile anyway. With no sprayer, I used wet wipes on the outside and then tried to swoosh the wound clean in a tub of water. Not very easy. With subsequent surgeries, I got the sprayer and just sprayed the wound out gently and learned to stop worring about it. There is only so much you can do. The rest you have to give to God to deal with and he knows what he is doing since he designed our bodies.
Also, I found that guaze stuck to the wound tissue. Hurt like blazes when I pulled it off. Everyone said that is good because it pulls off dead tissue. Good! They can do it too themselves sometime!! (I really pity burn patients because that is what they do to them. I would need morphine. 
) Finally, a nurse said to wet the guaze with sterile saline before putting it in. The salt keeps the wound sterile and promotes healing, and the guaze will come off much easier. It is wonderfull! You can get sterile saline at the pharmacy. My doctor's assistant actually wrote me a perscription for large quanities of sterile saline and I got it for dirt cheep! It is best not to use regular water because it isn't sterile and doesn't have the healing salt.
I suggest you get you sister to look at the wound every day or so. I know this is gross on many levels and a lot to ask of her, but it is good to have a second pair of eyes watching the wound to make sure it is looking OK. My wound hole actually got larger at first. What happens is that the skin stretches and the wound flattens. Hard to desribe, but all quite normal.
Don't be bashful about calling your doctor's office if you have any questions or concerns. That is what they are there for. He has a nurse of phyician's assistant that may have more time than the doctor to take your call. In my experience, nurses are compasionate and will spend time on the phone with you explaining things and giving suggestions. This is your first time (and hopefully your last) so of course you have questions!!
As to the time for the wound to close. You won't like my answer. Lets just say weeks. I don't know how mine compares to your and there isn't a hard and fast rule. Unfortunately, we Crohnies heal more slowly too. And immune suppresser drugs will slow things even more. I asked my surgeon about when I could start sitting and when I could go back to work. He said whenever I felt good enough -- but that the longer I was off the wound the faster it would heal. Sitting on an open wound is not good for it. You stretch it and how can you keep it clean at work?? The last thing you need is for it to get infected. That will just delay things. So I know you won't like me saying this but prepare for a least 2 - 3 weeks of at minimum (mine took 10 weeks). Have a frank converstion with your boss and ask if there is anything work you can do from home. See what he says. Don't get pessimistic until you talk to him. You don't need to tell the boss exactly what you have (eekk!!), maybe just that you have had surgery and have a significant incision that will take time to heal. Offer him your doctor's phone number and ask if he needs a note from your doctor. Try to not be so hard on yourself if you physically just can't go back until the wound closes -- even if that means weeks. I truly hope this is not the case and you heal rapidly!!
The best thing to do now is to sleep, and fill your time with happy things like cheerful movies and books. I am praying for patience for you and quick healing! Take care!! And congratulations on being on the road to healing! That abscess is GONE!!!