I was switching to the most profitable coin every time the profitability changes, and used to convert that coin into either BTC or ETH. Still, ETH is the most profitable coin for the past few weeks and there is nothing close to it.

Switching to coins which are less difficult to mine does hurt you in the long run. Assuming that you love the less difficult to mine coin, instead of mining it, you are better off mining the best profitable currency and convert that to the coin you love - that way you get the most from your mining.