It's not the best to be heavily invested like this, but... I'd say it's not the worst timing to be buying more STEEM neither.
Second but... I hope you also have an exit strategy ready. STEEM is not just going to go up and then stay at that level. It will crash down afterwards.
In my opinion, when/if the price starts going parabolic, it's time to start powering down. Later on, there will be a price level where you can buy in with Euros once again.
If you don't, you will likely be missing out on one/several million(s) of Euros in profit.
I understand you like STEEM like a lot, but it's not a religion.