Your champion pick is good, your build is good, but the enemy lux is too fed. It's hard to say exactly what you could have done differently when we didnt see the match but I think you are on the right path. Also the fact that your posted this, understand you didnt have the best score, want to improve, and are not salty; are the reasons you will succeed.
1)Your gold and exp income is quite low, possibly you need to run gold and exp boosting runes and masteries; or stay in lane longer and dont miss out on valuable exp roaming too early not getting rewarded.
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I can see 3 or 4 of your deaths were in the exact same spot, below tri (near golems). Possibly your vision in that area is lacking and you are finding you are getting caught there a lot, try warding that area more in the future.
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You guys still managed to keep the dragons 2-2 which is impressive seeing as how fed mid seemed to be getting, good warding. On the flip side u guys lost a lot of towers so maybe if possible you could leave lane and rotate to help your teammate is he has 2-3+ people in his lane pushing it down.
How long have you been playing? You will rank up if you keep trying to improve :)