Invest as much as you can in Bitcoin, you will earn income even when you sleep. You can sleep soundly without having to think about negative things such as losses or so on, as long as you are able to maintain the security of your private key well, nothing can make you anxious about the assets you store.
I chose one of the three ways you mentioned, namely Bitcoin. DCA is a strategy used when investing, you can buy Bitcoin consistently with the same amount at regular intervals. When you already have Bitcoin, believe me, you will sleep soundly and Bitcoin can also increase your wealth.