Do I need to change all my coins to ETH or hold the coins until their price go up? What will be the best option for now?
It depends on what coins that you have, if there's a good potential why you change to Ethereum?
ETH has a great potential and second to bitcoin good for long term.
But I advice to you if you're coins have a potential it's better to hold both ETH and your coin.
The answer to this question actually resides from the
reason for acquiring those coins... it is supposed we buy some coins because we love the project behind them and we believe their price will
increase over time, right? During this dip, most of the coins dropped their value more then Ethereum, so it seems not a good idea to sell them right now.