dp/dr?

Hello everyone. 2 weeks ago I got a sudden panic attack while reading some philoshopical stuff. It doesn't usually give me panic attacks but since I was a bit drunk, I think it might be the reason I overthought it. I was absolutely fine before, but after that, my life turned into hell. At first, I realised mortality of everyone I love, I cried for a bit and then started thinking about existence, time and everything related. Everything started to feel pointless and unreal. I didn't want to eat or do anything, nothing would bring me joy. Everything seems fake, dumb, unexplainable. I couldn't sleep at nights, terrified by all that thoughts. Then I started to think about what could be waiting us after we die, and I got obsessed over a concept of eternity and got terrified again. Now I'm feeling kinda better (I eat, sleep better, do things I liked to do) but I got hyperaware of time and existence and it feels just as horrible. I think about how anything I do is already in the past and it's just killing me. Whatever I do, I just get thought of how it's already in past, already happened, time only goes one way. I just can't deal with it. My life is normal, nothing is stressing me, everything is ok, but all this existential stuff that popped into my head after 1 panic attack makes it so much harder, so unbearable. Is there anyone who experienced/experiencing it? Is it dp/dr? Or is it depression? I feel lost and I would really like to hear your opinions. Thanks.