Java SE Binary (64-bits) has stopped working - no apparent reason

[ Subject : https://i.gyazo.com/659a11cd47126049008c08d17785d127.png ]

Hello,

I have recently decided to play again on Minecraft, since one of my friends server had reopened. But, the first time I tried to join after I entered its IP, I instantly crashed one second after connecting, just before the chunks even loaded. I tried again, then the chunks started to appear, but, again, crash. And each time I've tried, I actually could stay longer. The highest duration was... something like 20 or 30 seconds, actually. It worked perfectly fine last time I played.

I uninstalled and re-installed Java maybe twice, and Minecraft once, carefully checking if it was the right version for 64-bits and all. But, now, I just can't stay more than one second on the server.
By the way, I also tried to connect on another server, same problem. I tried in solo game, no problem at all! So at least I know Java crashes when I try to play online (I think).

My computer isn't bad, I clean it every week or more, it is optimized for gaming essentially, I know I have high FPS (60~120) on other games, my ping is low and constant (36ms), when Minecraft is being executed, it takes 45-50% only from my processor (am I clear with "processor"? Not english native).

Please ask for further details if they are needed.

Myrioka.