If you have concerns about complimenting your partner regularly because you don’t want them to “get a big head”, that in itself is concerning. Why does an increase in their confidence threaten you?
jane austen is timeless because the line “i’m 27 years old, i’ve no money and no prospects. i’m already a burden to my parents and i’m frightened” is as relevant today as when she published pride and prejudice in 1813 😭
In a relationships I rarely concern myself about whether my partner is cheating on me/not. Nothing you can do to control that. That level of paranoia is not healthy. Focus on being the best partner, if you discover they’re cheating. Do whatever you need to do with it.