Long-term hold has been a bit tricky now with the growth of bitcoin. You said you bought ethereum worth 50$ few months back so here is the question you should ask yourself first like you want to increase your BTC value or just USD value. If you are looking to just increase your USD value then you are in profit but if you look at Satoshi value of ethereum it has gone down a lot.
I myself is a long-term hodler but now i am realising that with this parabolic growth of bitcoin. we are actually losing by investing and hodling ethereum(though it does not apply to all the altcoins).
As your investment is small maybe you should sell @15$ profit.