Tips to improve my game

I just started the new season, ended off at s2 with probably average mmr. I went 4-6 placements, probably my worst performance I've had in a few months. Got placed in bronze 2 and almost got to promos. Then I lost 4 games in a row. Now the problem is I have been doing exceptionally well in some of those losses but can't seem to find a good way to carry or win a game without something happening. I really want to invest time and get better at this game but I feel like something is holding me back. I would love any tips that could be offered to help me improve.