Hi and sorry to hear about your diagnosis. I also have a perianal fistula and have had serious issues with perianal abscesses. My abscess was so severe I ended up in the ER with such intense pain I could barely breathe. I had it surgically drained and it came back as soon as I was released from the hospital; basically I had it "drained" twice in the same week and since then (that was in February) I've had issues with pain and drainage. I don't mean to scare you. I think everyone has a slightly different experience when it comes to these things. I have severe perianal crohn's and have been having difficulty getting into remission as I've been pretty refractory to all treatments so far (Remicade, Humira, Methotrexate, Imuran, Mesalamines, etc). I know that a lot of people have had success with the Cipro/Flagyl cocktail keeping their abscess situation under control. My body is hyper sensitive to medications so when I'm on those antibiotics I get severe diarrhea to the point where my doctor won't have me on them anymore (we're trying Xifaxin, which is much more gentle on the system, but we're battling my insurance to get them to pay for it).
Perianal disease and fistulas are tricky and not always easy to treat. They can put something called a seton in the fistula to keep it draining and in theory prevent an abscess from forming. In my case the seton insertion actually caused the abscess because of the prep and aggravation to the area, but that is definitely not typical. I don't have a seton now because the second abscess drainage they did on me they cut a pretty good hole in my rectal area so it is always draining (not the most pleasant thing in the world). The antibiotics should be helpful, but you should also talk to your GI about getting on biologics. Biologics can help close perianal fistulas and can really help with perianal disease. I've been told that Remicade is the best for that. It's what I tried first, but unfortunately I was allergic to it complete with anaphylaxis and serum sickness.
I know that this can be pretty overwhelming and perianal disease is hard to deal with both physically and emotionally. Besides the antibiotics are you pursuing any other treatments? I know how bad the pain can get. Make sure you let your doctors know and don't be afraid to ask for pain killers if you need them. There are effective treatments, they just take time to kick in sometimes. Definitely talk to your doctor about Remicade. It has helped so many people and could really help with your fistula (it does work for most people. My reaction was literally something that occurs in less than 1 percent of patients).
In addition to the biologics and pain killers, I would recommend getting a heating pad and sitting on it from time to time (or laying). It can help with the pain and also keep things draining. Sitz baths can be helpful too.
You're not alone with this! I know a lot of people on the forum have dealt with fistulas and abscesses. They're no fun, but support from people who understand and have gone through it is also incredibly invaluable so don't hesitate to reach out here for support.