this situation happens almost every bull run, it's always BTC that runs wild the first and altcoins follow. BTC in this bull run though is just different than how it did in the last few bull runs. the ETFS must be the ones that make it a lot different.
waiting is the game. you have missed a lot already since the time BTC started rallying, selling your altcoins now for BTC could be too late and by the time you look back, you'll see your altcoin gains will also go up. if possible just come up with a new capital in buying BTC and just leave your altcoin investment alone.
And by the time the focus shifted to altcoins, a great deal of new projects may have merged which could reduce even further the interest the community may have on investing in that coin in particular.