How can I play in a better way

Hey, I´m new and started at 18.3.
My Team ist at position 1 in our league but in the most cases i only win 1:0 or 2:1 and make the goal(s) in the last 5 minutes.
The strength is at 15,7 and the opponents strength is about 12-13

Here the team

-------St(-->)(17)--------St(-->)(19)--------
------------------AMC(-->)(21)-----------------
------MC(17)------MC(<--)(16)---MC(18)---------
----------------------------------------
--DL(21)----DC(<--)(16)-----DC(<--)(16)---DR(15)--
----------------------GK(17)-----------------------

What can I do better? My biggest problem is the low number of goals i make.
A other problem is, that I have always 1-2 casualities after a match despite the fact that i start every match with 95-99% condition. I have no explanation for that. Why

Your quality vs your opponents is marginally better so the results you are getting is normal, you need to buy better players.

Also as far as injuries are concerned, get used to it, this game is programmed to give you injuries often.

But it can't be normal, that I have 5 injured players in my squad. I have 5 MC's and they are not enough.
Is my lineup okay with the red and blue arrows?

Sorry for my english :D