Question. What should I be spending my stamina on right now?
I think that depends on what your goal is: maximize coins? maximize xp? There are a lot of options between h2h, seasons, lvl, and events/longshot. Me personally: I go for the free 80 ovr players first, then try to build up game plan & locker items for those boosts. The daily objectives are a must-do as they have some of the best XP awards to keep your stamina high (on level ups). If you want to build up your locker items, play seasons. If you want to build up your coaches, play h2h. The good news is you can use the info in the spreadsheets to find out what things cost and what they reward so you can plan out in advance, to whatever best suits your style.
PM me and I'll help get you set up. As long as you have excel or google sheets it should be ok. In addition, Tee just updated our clan's online version too, which may get you to some of the information via web page.