I'm really sorry to hear that this is going on with you. Know that I think you are at a time in life in which a lot of people really struggle. You just graduated and presumably, that means it's full on adult time! Job, living situations, relationships all can shift/change and it brings on anxiety. Panic attacks are terrible. And I'm not so sure you are suffering the 'aftermath' of a panic attack as you are suffering symptoms of ongoing mental health issues. Please don't feel like that is a bad thing or uncommon . . . one in four Americans is on an antidepressant! So, I have to ask you how you are being treated for this situation? Do you see a psychiatrist? Or is your general practitioner overseeing things. Both can work to varying degrees for people (as all doctors and people are different in terms of ability and reactions to their healthcare provider)-- but you seem to have significant level of anxiety and depression that is getting worse to some extent and really impacting your life. I'd consider a psychiatrist. And talk therapy is so important as well. Panic/anxiety/depression can be greatly helped by medication but working through it with a psychologist, doing CBT, talking about triggers and coping methods all is essential. The best approach is often involves both these elements of treatment. And what you do out of treatment impacts things as well. You sound exhausted. Some of what you have, I had once when I was so sleep deprived, I was getting sick. So, check your level of sleep (too much, too little) and balance. Eat well. Take a good mylti vitamin. Exercise most days of the week. Learn meditation (they even make some great phone apps these days to help), try yoga, learning calming breathing techniques.
It's hard to give a time line as each person is different in what it takes and what they need. Medication, once chosen, and on board can start working and be effective in 6 to 8 weeks. That's a general time frame. So, let us know if you have a doctor you work with or what you do for the anxiety/depression/panic.
I would think that the other symptoms (besides being related to the stresses of school and lack of sleep and all) would possibly bunch with the panic attack, but not necessarily be caused by the panic attack. In fact, the panic attack could be caused by one or more of the other symptoms. As the above poster says, it's time to do some self care, and to see your doc or therapist.
Just to say again, because this is repeated so often lately on here, the only. reason 1 in 4 people is on antidepressants, if that's even true or is just one of those memes out there, is because drugs are way overprescribed in the US. If truly the US has that many more mentally ill people than any other country we really really need to find out why, don't you think? As to the poster, there's no such thing as depersonalization and derealization apart from some other condition -- it's a symptom of something else, not a thing in and of itself. It can be a symptom of anxiety or depression, but it can also be a symptom of a physiological problem, as can an anxiety attack. So my first question is, was that your first anxiety attack, or have you been diagnosed by a psychologist or psychiatrist with anxiety attacks before that? I'm asking because as I said, a lot of physiological problems can cause anxiety attacks and the disorientation you're feeling. Examples, some of which are listed above, are lack of sleep, dehydration, lack of electrolytes, lack of Vitamin D, lack of B12, lack of iron, other nutritional deficiencies, thyroid problems, blood sugar imbalances, overuse of recreational drugs especially alcohol, eating irregularly, food allergies or intolerances, hormonal imbalances, hidden viruses or bacterial infections, etc. Have you ever had an extremely thorough physical exam with a doctor who seems thorough enough to care to spend the time it takes to do it to make sure this isn't some other problem than a mental illness? You are also at a point in life when two things happen: it's the age when mental illness tends to break out and become chronic if it's going to do that, and it's also an age when some people feel a lot of pressure because it's the true beginning of adulthood, assuming any human being truly matures to that. It can be a very tough time and that might be your problem, and if it is, therapy, not medication, would be the appropriate avenue for you so you can figure this out. You may have a lot to figure out and are not doing it well by yourself. If the psychologist decides you're not coping at all well with life he or she will recommend you see a psychiatrist for medication. Now, it may be you're a chronic anxiety sufferer and depression sufferer and you've already been diagnosed and been through all this stuff, but we don't know that from your post and so telling you what you're suffering from and what do about it is impossible for us. We can only tell you what might be happening and what you should do to find out. Best of luck to you.