The best decision is investment compared to trading. OP also said that he had just started trading, so this was purely OP's mistake in choosing to place that much money in trading instead of investing.
In my opinion, investment is definitely easier than trading, but not so easy that even a newbie can invest easily. Trading is a tough job and requires a lot of experience and skill, while investing also requires knowledge. Market volatility bear, season bull season, previous record and history of any coin, current season information about all these is very important. Only then can we be a good investor and make a profitable investment.
There are also people who bought Solana at $200 and bought Dot Coin at $40.Now you can see the current price of both where they are trading. Similarly, you will find many investors who bought Bitcoin around $50,000 and then the price of Bitcoin has dropped to $15,000.These will surely be people who don't know about investments and invest without knowledge and information after watching the price of Bitcoin decrease.
The stress and pressure caused by both are also different. Trading has a higher level of stress and pressure because this is influenced by market price volatility at that time as well as several take profit and loss targets during the trading period (short term). Investment is clearly different because the goal is long term.
As you explained, although investing is relatively easy, it carries big risks and tends to take up time. To achieve satisfactory results we are also required to master basic things regarding market analysis and sentiment. If you invest haphazardly, the profits generated and the time required will be a little unequal. However, if we master the basics of analysis, perhaps the investment time and funds used can provide maximum and satisfying results. And events like buying at peak prices as you say will not happen.