Going up 3,4 goals in first half and then conceding 3,4 goals in the last 30 mins. How can I prevent it ?

So before the patch I was winning 3-4 or 2-3...same goes for loosing apart from some outliers. Now after the patch I win 5-6 or something but my biggest concern is, that I score 3 to 4 goals in the first 60 mins(70% of the games) and then at 90th minute, my opponent either completes the comeback or they're just one goal behind. I've tried changing the style of play as well but no luck I know it's a skill issue and I am willing to learn if there is anything I should focus on I play 433..I tried switching to 4411 and 4231 but no luck Thank you in advance