So if it's too much for you, start looking for a new job right now. As somebody said in another thread - if the possible severance is the only thing that's keeping you here, give it up. No amount is worth the cost the wait might have on your mental health.
It's always easiest to find a job while employed. If you're unhappy, look for a job and quit once you find one. Is the monetary gain from a severance package worth the risk that when you do get involuntarily impacted that there will be enough jobs available given the number of people suddenly looking for jobs?
If you're waiting on a severance package, you are giving Cisco all the power. They get to choose when to let you go, how much of a package to give you and managers get to plan who to give your work to so that the work keeps getting done. In the meantime, you're the one suddenly looking for work, worrying that you'll find a new job before the severance runs out and how you'll get by on the reduced income until you find that new job. All the risk is on you, not Cisco.
On the other hand, if you look for and find a new job, then give your notice of two weeks so that you quit Cisco and start the new job the next business day, all the power is in your hands and Cisco has all the risk. You're not dependent upon the job market being hot because you can take your time looking for the job that's a good fit instead of taking the first one that's offered because you're burning through your severance package. You can give Cisco 2 weeks to find someone to do your work, or not if you're in a right-to-work state or your employment agreement says that you or Cisco can end your employment at any time for any reason. Cisco now has to go through the red tape process to post your job, collect resumes, conduct interviews, perform background checks, and on-board someone. By the time they get their PC ordered, accounts set up, and all of the accesses they need to match what you had, they're a good 2-4 weeks behind even if they find a candidate in that 2 weeks of notice you gave, and we all know Cisco can't hire someone that quickly. That means that someone on your team, unfortunately, has to pick up your work until your position gets back filled.
Let Cisco bear those costs and difficulties instead of letting Cisco keep all the power and you have to deal with all the difficulties of finding a new job quickly.