why the price went down? I do not understand, increasingly deteriorating situation
Because it is the way it should be. Appetite grows within eating. More you BTCs have, more you want them to grow your funds. Just ignore those price fluctations, if it makes you anxious. In such state you can make wrong decisions.
Just answer yourself to questions:
Is here a strong reason to dump?
What is market cap of this coin if compared to other coins, either- those, which are developed actively, those, which are left drifting in crypto ocean?
Do you really want to profit?
If you dump, which will be next coin to invest into? Is it reasonable to do at this very moment?
Do you want your profit come from long term investment, or risking with swing trades?
etc.
I am suggesting to hold now. Definately price will grow... but if you are impatient to get profit or you are very anxious person, crypto trades are not meant for you!
After more than year I just started to be able to control my emotions while making decisions. Never blame yourself for mistakes, never regret. Learn and go further!
There is a lot of money around you. Just learn to grab that apple from tree.