I unexpectedly saw my deceased colleague and I’m finding it hard to process. What practical advice can you give me to better cope with the stress?

I can't help with your processing this situation, and I'm so sorry you experienced that. I have however suffered with panic attacks for a number of years so I can offer some practical advice that might help when you have them. First of all, start to recognise when a panic attack is coming on, there will be some signs. For me, I get very clammy, my thoughts start racing and I feel very tense, like I'm on high alert. The best time to stop a panic attack is before it comes in full force. If you do feel one coming on, stop what you're doing if it's safe, take some deep breaths, and try to remind yourself that you're safe and you're going to be okay. If the panic attack then does come on, you need to find a safe place where you're not going to be distressed further. For me, this is lying down alone, for you, it might be somewhere different. Have a plan for when you're at work or out and about for a place you can feel safe as you ride out the attack. Then, take some deeps breaths. Focus on breathing in through your nose and out through your mouth - there's no need to count and hold (unless that helps you) - just slow, focused breaths. Often during panic attacks you can get the sensation that you're about to die. You're not, and breathing slowly and steadily helps to calm the nervous system. I like to rest my hands on my ribcage at this point to feel the breath going in and out, to remind myself that this is my body and I have control of it. Secondly, find something relaxing to listen to. I usually find that I can't dispel a panic attack in complete silence, so I usually put on some white noise to keep that part of my brain distracted while I work through it. I use an app called Sleepa where you can mix and match sounds to your liking. It doesn't necessarily have to be white noise, it can be music, a podcast, audiobook, YouTube video etc. as long as it works as background noise. Now there are a few options. Often at this point, my panic attacks start to subside, and if that's the case then I try to still stay relaxed, almost like decompressing. Panic attacks are stressful and throwing yourself back into whatever you were doing whilst panicking is a recipe for disaster in my experience. At this point I like to imagine myself floating on a river, with my thoughts and feelings flowing through me and out of me until only I remain. If at this point you haven't stopped panicking, then distracting yourself can be a good idea (but it's better not to lean on distraction as that doesn't resolve the core issue). Sometimes for me that takes the form of playing a game on my phone, something which takes brain power away from panicking and onto that thing - think something like Suduko or word puzzles. But sometimes you can't handle looking a phone, so playing a game in your head, like naming a food for every letter of the alphabet, or grounding yourself by recognising your environment (5 things you can see, 4 things you can hear, 3 things you can feel etc.). At this point my panic attacks will usually subside, but if you're still struggling then just keep breathing and doing your usual activities until you calm down. Don't focus on the time or how long you've been panicking, just put all your mental energy into calming and getting yourself out of that state. It might be helpful to let someone know that you're having panic attacks, then if you're around them when one comes on then they can help you ground yourself, but its totally okay if you don't feel comfortable with that - these techniques work alone or with other people. Apologies for the wall of text but I hope this helps with the panic attacks, and that all the other advice on this post helps you. Take care.