Before going into investment there are things you need to understand, such as market volatility which comprises of ups and downs of the price movement and you should also understand that the market is not always Rossy all the time because it has the troubling time and also the profiting time, so if really you believe on the potential of the coin you invested there is no need to panic even if the price has gone very low, however I wouldn't advise you to sell your investment because you will seriously be at lost since you bought at $3000 and now it has dropped to $2500, so I would suggest you have more patient because the entire Market is currently on fire, so is only ethereum that's affected but also to many other coins including Bitcoin, however what I would only advise you is that before investing on a coin you should really know if there is any potential about the coin so that you will not get panic because if you had understand ethereum you wouldn't have panic because I no eventually it will come back to the price you bought it, though for me I focus majorly on Bitcoin investment.