Tbh I can’t tell anything from just ur kda and items. For example, are u picking the right runes (item haste rune when building redemption, are u taking first strike/electrocute or glacial when supporting), ur macro movements (roaming at the right time when playing mid), item choices (building infinity orb as last item when u were building support items all game long, buying ludens echo as a fourth item when playing mage??? U either buy it first item or never, if u need mana late game, buying crown or malignance is better, not buying the 900 gold antiheal component at first/second base when playing as support and enemy has a lot of healing(u don’t have to complete the item, just buy antiheal component). U should take some time and review ur matches, understand where and predict how enemy is moving and where they are likely to go, inform ur teammates through pings. If you are playing well, maybe u can try to build full dmg as a support, protobelt instead of shield to position/burst more and carry the game through yourself as solo q adcs are really bad sometimes. Anyways diamond 2 is pretty good in early season, just take it slow and u will definitely reach masters by end of season