I Need Help

I'm new to LoL and its community so please bear with me if i posted in the wrong category, or did something else stupid :) I started playing League in February this year, and frankly, I suck in ranked. After I played my placement matches, i was placed in Silver II. In normals, I often carry the game. However, in ranked, I usually end up giving the enemy laner first blood by level 5. I have trouble balancing CS and harass. Usually, my foe heavily harasses me and i have to stay at tower/back because of low HP. I also lose a lot of CS and exp this way. If I try to harass and deny CS, the enemy often starts using their full combo on me the moment I poke, so i end up having to play passive. If i don't back up after they all out and i try to all-out them back, i die. But when the roles are reversed, i STILL die! It doesn't matter what the lane is or what champions are playing. I have about 150 wins in normal, so I'm sure that many of you will tell me to play more normals. Frankly, i got bored of normal's and wanted to play with players that are better than me to learn from them and gain elo. Sadly, i do not have any IRL friends that are helpful or constructive, and league isn't that popular in my area; i only know about 5 people that play league. Currently i am playing custom games to improve my last hitting, which is pretty good in custom games. My weakness is CSing while under pressure from the enemy laner and getting away with harass. So, I am begging all of you in the community for tips about the laning phase. I will greatly appreciate any advice and constructive criticism, and I have provided the link for my match history.