Bitcoin is and always will be very volatile, but this does not mean having to give up his purchase. If you look at the chart of growth rates you will see that every year the price of bitcoin is increasing. This trend will persist for a very long time so you can buy it at any time.
so i should buy bitcoin at this point or when the value reduce.
Try to wait for the price to decrease a little. Last month is the best time to buy bitcoin because it dumps back to one thousands. It is so rare to see the bitcoin price to go back to that kind of price especially with a lot of users. I think you are late buying some bitcoin, maybe wait a month or longer.