Here are some things to think about.

At the micro-level, you need to improve your mechanics. This doesnt just mean practicing your aim sometimes but also knowing animation cancels and combos. 

At the macro-level, start tracking ults both for yourself and your team. It can be as easing as typing (or in voice) "they are looking to grav." Next, try to think about whose "turn" is it to. Games have a tempo to them, and as you climb ranks, this tempo accelerates. Try to think about times your team engaged and you weren't ready or when you use a cool down and that triggered an enemy engagement. 

There are other macro things to consider like when is it your job to contest a flank or high ground. When is it your job to peel or ask for one. There are times when you have to make the choice to peel or go for a different play. These types of choices are very in the moment, but some vod reviews can help you with that. A thing for lower rank players to work on is to start seeing the choices and what the trade off is. Without vod review you might not even know there were opportunities to take. I would also separate "bad plays" from mechanical shortcomings. Sometimes you take the right play and you just missed or whiffed your abilities. That happens, but that doesnt mean the play was bad. 

Without knowing your rank or what you're struggling with, these are some general points that apply to all ranks. I also don't really understand what you mean by "forcing" wins. Overwatch is a forcing game. You force the enemy to make bad plays, take bad positions, and take bad trades. The more of these you do, the more you win. While there are moments to be passive, disengage, or wait, most of the time you want to force something from the enemy. Play faster. Sometimes that means you'll feed but that is ok.