I feel your pains bro and most people have been there. It is a whole lot of money to lose, but I am happy you realize your mistake and you are ready to make some adjustments.
First and foremost, take a deep breath, it has happened and trust me mate, there is nothing you can do about it, at least for now. The first mistake was going all in on those altcoins and not practicing risk management. You should not even be trading the whole 600btc, but just some few percentage of it (20% is good enough as far as I am concerned with the amount you have). Also, since you believe more in increasing your bitcoin, you should not even use more than 2% of your trading portfolio on a single alt.
Secondly, you already know by now that when you are trading without any strategy, then you are gambling which is what you absolutely did. The only good thing I could see here is that you chose some pretty good coins, but just unfortunate you picked them at the top. Here is all I just need you to know next time before telling you what to do with your present loss based on my opinion.
1. You will be better off with long positioning style of trading and 4hr or daily chart should be your best option. Also, always watch out for bitcoin's movement more as it kind of controls the market; if it is dumping, other alts are taking the hit and same happens during bull run on bitcoin. The only time when they rise hugely is when bitcoin is taking some rest if you know what I mean.
2. Learn how to trade by following trend for long position. The use of MAs will always help, and learning some other few indicators such as MACD, RSI will help as well. You can also learn how to trade with candles (make sure you are using at least 3 strategies to make your decisions).
3. As long as you know you want to trade, learn to leave your emotions aside, and remember that stop loss is always the best language of every trader, but a minimal one. (Usually, you cannot do all of these without knowledge).
4. Once on the daily chart of any coin of your choice, make sure you are picking them from the bottom, and they are either changing trend or they are totally oversold which the RSI can be of help with that. MA crossing shows that a trend is changing but that does not mean you should just relax and not monitor your folio.
5. All these should guide you on how to make some research on what to learn on google, and you will be so surprised how simple it would be for you. However, after learning, start with just very little to build your skills and have some confidence from the experience you end up getting.
Finally, you have so much altcoins to monitor at once, so try reducing their numbers next time and put a buy order only when you are sure without forgetting the stop loss. Also, based on what you are holding now, it is already unfortunate you are holding them, but you have just two options.
a. They are good coins, but most altcoins have their season, so if you can learn fast, you can watch out to see how they end up doing for a while, as they will definitely pick up, but do not expect big gains anytime soon, so try not to be greedy and watch for the best time to get out once you have finally made good profit from some of them.
b. Watch out for change in trend of bitcoin and trade against fiat, but you still cannot do this without knowledge but if you can learn how to trade a breakout from downtrend channels, that would help. Hopefully, you will be able to take advantage of the swings, and then increase your bitcoin. However, please do not do this without learning as you will get emotional and even lose more.
For everyone in the OP's shoes, don't ever trade without learning as there are so many resources on google you can make use of, and even if you learn, no matter how much you have, start with very little you can afford to lose, and see how better you get. Do not rush, because the same way you rush in, you will end up rushing out with huge loss. You should get a lot of resources to learn from with this website.
https://tradingstrategyguides.comI wish you the best of luck!