In-game Glitch occurring more then once

Today I played as Orianna, when I entered the match, I could not see the health/mana/lvl bars above my and other character, and on my champion stats on the bottom of the screen, my health bar was black, with a line indicating at which point my health is, and that line some times disappeared, leaving me with no clue of how much health I had, but the mana bar was fine. While laning, it really annoyed me that i had to click on the enemy champ to see his health, and me not knowing how much health i had made it even harder. On the tabs menu, all the champs where grouped up in 1 slot, and I had to keep clicking it to see the desired champ, to which it switched when i closed the menu, I also could only see 1 teammate above the map. Even worse was when the enemy I was laning against "disappeared", I could see his bombs coming at me, but not the champ, and after that he suddenly appeared RIGHT in front of me, and leading to my death since he hit me with everything. After that, I quit the and rejoined, which fixed the problem, but made the match unplayable since i was 5 lvls behind everybody, everybody had 3 times as much cs, and i was focused since i was very weak. This has happened befor but not to this extent, and hope the problem doesn't show up again