Antibiotics kill a lot of bacteria in gut health which leads to many problems. You should start taking some probiotics which can help you with antibiotics as well as IBS. Here are some tips that can help you start exercising regularly, make a fixed schedule of eating, avoid foods that trigger or symptoms, drink lots of water, and try experimenting with fiber, it can help you with constipation but it can create gas and cramp.
You can check this to get a better understanding of IBS and Probiotics.
Antibiotics can be really hard on the stomach. You've been on a bunch, so I'd give it some time before worrying if it's IBS or not.
You're taking probiotics, which is great, and what I'd have suggested, so just give it all time to settle.
If you look up an IBS diet, you'll find all kinds of different things - high fiber, low fiber, low FODMAP, etc. Right now, I wouldn't even worry about that. Just go bland. You'll figure out fast what works for you now. Typically, when you have an upset stomach, you figure it out quickly. It may be soup and toast for a bit (avoid breads with a lot of grains, though), or maybe you'll be able to handle more.
If you're eating a lot of fiber, make sure you're drinking lots of water. It might be that you need to avoid dairy for a bit, or spicy foods - everyone is different, so I can't tell you what will work for you. Start bland - low salt, low salt, softer foods, low fat, low fiber, generally not fried, etc. - and go from there. Avoid alcohol and caffeine. (Yes, it's as much fun as it sounds lol.)
If things don't calm down in a few weeks, then you can start thinking about things like IBS, but for now, I wouldn't worry about that. You're stomach's been through a rough time, and may just need to settle.
Let us know how you are. :)