When I knew about cryptocurrency I went for research and I discovered Bitcoin and other coins in the market, I went to study the history of Bitcoin and it's growth and I saw how well it was, so I said to my self if Bitcoin can grow this big then I needed to fine a rising coin that has not grown too big and invest my money on it, thinking it will grow as Bitcoin did, this happened 6 years ago.
Many people have similar experience including myself. I have long made peace with myself and I will advice you to do the same because you cannot change the past, just take the lesson and make the future better. On that note, what are you doing now that you know that Bitcoin is the way forward? Bitcoin is still very fine for investment now, there is a fixed supply and there is halving event that will always create the needed shortage of supply to push demand up. It might look too high for some people but it is not really high, you can buy a fraction per time and continue building from there. So like I said, it is not something to regret but an opportunity to gain experience. So cheer up and continue building.