How to prepare yourself for the terrible two?

I have a baby turning into toddler, she’s about 15mo and is starting to have a lot of opinions, and starts to throw tantrums. I find myself can be patient with her most of the time but dealing with a baby also let me discover I can lose my cool real fast when I am sleep deprived. I know there are going to be more sleep regression to come, and a loooooot more tantrum. How can I prepare myself for it? Any good tricks on developing better patience/mental capacity or any tips on cooling yourself down quick in front of a tantrum toddler? A little back ground of my life is I am by myself with her half of the time, so there will be times I cannot just pass her onto another adult. Thanks in advance!

Edit: thanks so much for all the response! Didn’t have time to reply one by one, maybe I will do them one by one whenever I have some down time. But I do read them all. Thanks for helping a distress parent 🥺