Panic Disorder- Or something else?

(This is partially a repost from my introduction post)

I suppose I'm looking for affirmation that what I'm experiencing is "normal" and curable... I want to make sense of what's happening to me, and to know whether this sounds like a typical 'mental illness' and not a manifestation of something physical or neurological.

Background: I have a natural inclination towards anxiety disorders. I struggled with OCD for 10 years, and have had short off and on bouts of depersonalization/derealization since I was quite young. I have also had panic attacks infrequently since childhood.

Two months ago, I accidentally received a high dosage of THC via an edible which plunged me into a horrific, helpless state for about 5 hours. I heard voices, couldn't walk, felt very nauseous, felt split from reality and had intensely paranoid thoughts. I was terrified for my life and for my sanity, and everything felt strange, ominous, and unfamiliar. Once this wore off, I felt more or less back to typical self by the next day. Fast forward one week, and I made perhaps the worst decision of my life. I decided to put a microdose of THC into my tea, and this decision spiraled me into a very, very dark place. I became intensely paranoid that I was going to relive the week before's nightmare. I felt as though I was sinking into the ground, and layed in bed for 4 hours trying to distract myself with phone games. After this period of time, I started to think I felt better and put on a show... then suddenly, a dark thought slipped into my head again and this time it hit me hard enough that I could barely breath... my chest and throat were so tight. I couldn't stand or walk for about 10 minutes. I moved myself outside, and sat there for 3 hours fighting to breath, scared I was about to die of suffocation or heart-attack. This panic lasted 4 days, during which time I went to the ER. They took blood and urine and everything came back normal. It seems this was an ongoing severe panic attack. For those days I was unable to sleep at all, and ate very little. After the 4 days, I went in and out of the panic state. Now after 2 months, I still have fairly daily severe panic attacks (or what I call "panic attacks", not sure if that's what they are). They most often strike me at night/dusk. They typically last for a minimum of 1-2 hours, but often continue until I fall asleep. During this time, I usually get severe nausea sometimes with vomiting, become dizzy and lightheaded, struggle to walk/stand, struggle to breath (even though I do not hyperventilate), struggle to think clearly, become paranoid, and feel totally helpless and scared for my life/sanity. I often also feel a sense of ominous dread, as though everything around me is evil and unfamiliar. I feel that I cannot cope with reality, nor can I cope with being stuck inside myself. Depersonalization/derealization sometimes accompany the panic attack, or may trigger after the attack and last anywhere from a few hours to a few days.

So... can anyone relate to this experience? Does it seem normal? I so badly want to get better and to return to who I was before this all happened. I miss my life. My school work/grades are suffering, and I can't really do anything out of fear an attack will occur and I'll be by myself or unable to get away. I also am struggling to cope with the attacks themselves... I feel helpless, scared, overwhelmed, and defeated. Everything feels sinister and "too much" for me. It's as though all love, warmth, and familiarity have been drained from my experience of the world... I'm terrified I'll never be able to regain a sense of normalcy.

Please, if you have any suggestions, advice, or have been through something similar, let me know. I want to believe I can get better.