The only reason I'm not worried about holding another 5 years (I don't have huge amounts invested, around $10k) is because so many institutional investors have jumped aboard.
Actual hedge funds and funds listed on American stock exchanges.

These whales dumping $500m+ into permanent Bitcoin holdings which they report as assets quarterly is nothing to scoff at.
If the market suffers so will they.

I have followed the same strategy with Berkshire Hathaway A series stocks. Check their price history on Google.
They do the most due diligence out of any investment company in the world. Their analysis is worth pure gold in its weight.

I have a portfolio dedicated to fully emulating Berkshire Hathaway ownership and it has paid off very nicely in the last 5 years.

Why do I think emulating big institutional investors is such a good move? Because they have so much to lose.
They have done a stupifying amount of analysis and forecasts to justify dumping hundreds of millions if not billions into these assets.

So am I worried about my bitcoin holdings long term? Not really. We can revisit this thread in 5 years.
At the time of this post on May 2021, the price per BTC was 32k each.