You're confusing two different things, here.
What you say about "psychology" is perfectly true, of course, but it isn't a reason not to read a book about the technical aspects of trading before looking at live charts: nobody can learn how to identify support and resistance without first knowing what they are!
It's very fashionable, these days, especially in forums, to attribute beginning traders' problems to "psychological factors", but that doesn't change the reality that most aspiring traders never make any money because they don't know what they're doing and the trades they put on never have any genuine positive net expectation at all. That's correctable by reading textbooks - not so much by gazing at charts or "mastering psychological factors"!
Yes.
You have to have an overall advantage (positive expectation) on your trades.
No money management scheme or mastering of one's mind/psychology will make anyone a winning trader or gambler if they do not have a worthwhile advantage on their bets.
Examples:
A. Every dollar bet is on average worth 1.01
B. Every dollar bet is on average worth 1.00
C. Every dollar bet is on average worth .99
Only the first example is positive expectation; aka, having the advantage, the best of it, being paid more than the odds, being paid more than is fair, etc.