In short, holding btc long term will probably make money. But holding alts long term is more likely to be better. Alts are cheaper and the risk can be spread. Not true with btc
It is a sure thing, if you had bought some bitcoins while the price is still low. Look at the price right now, for sure if you had sold some of it earlier. You will regret that you started to sell some of it but if you are able to keep them up to now you will be proud and happy that you believed bitcoin and you are able to hold them for better.