It's only natural to be afraid of being fired from your job, especially if you don't have money saved up and/or you have a MI that makes it difficult for you to get another one.

You never know what the future might hold, therefore, I think it wise to always have some kind of contingency plan in place such as an extra source of income doing something independent from your job (such as selling on eBay or driving for Uber), have money saved up to cover your basic living expenses for several months or more, or have somewhere else you can live such as with a family member just in case you're fired.

Call me cynical, but I simply cannot and will not trust somebody with any kind of direct power over me, especially an employer who is only interested in profit.