went 2-8 in placements, ended up in silver 4.
total now 28-20 overall and in gold 3.
placements/promos are always garbo, the secret is to play when little kids cant play, and you are going to get at least adults, not mechanically the best, longer queue times, but at least they're mature enough to make decisions.
if you want to stop losing games the best way is to take out the enemy teams best player. you wont guarantee your teams success, but you stand a lot better of a chance than just picking on your laner or putting team fights up to group members wondering if they're going to do what they're suposed to or not.
(im looking at you sona who absolutely holds onto her ult as an escape mechanism instead of an engage tool or instead of hitting all 5 of the enemy team you use it against the 1 tank out of panic to save your own life)
if you take out the enemy teams best player you will see results.
in the event you are losing lane and 1v1's against your lane opponent then i cant help you there other than to learn more about your champ, practice it, find what works, and attack the enemies mistakes.
best advice you're ever going to get
128 (3.1) CS in a 41minute game.
work on killing minions instead of dueling it out with your lane opponent. in the event your lane opponent only wants to fight you should be able to win at least 50% of the time. if you cant then hes just better than you or you are inexperienced on the champ you are playing.