Fear can be fear of missing possible profit but the more debilitating kind of fear for traders is fear of losing money.
I wish we had a different term than loss or loser or losing - these have so many negative connotations from previous teaching and experience in life that its no surprise they can have an emotional impact on traders.
Another way of looking at your losses is they are just bills - like utility bills or the cost of updated IT equipment or the local property taxes on your house/office. If you have a profitable system, it will feature some trades which do not generate a profit. But that is inevitable, these are not avoidable losses, you cannot control which trades make a profit and which don’t. So these are just overheads you have to pay on any business. Don’t think of them as losses.
Real losses are those which you can accept tor refuse - such as the trade that broke your set-up rules, or the stop that you widened as price went against you, or the trade that you doubled up to get a previous loss back.
But don’t feel guilty if you’ve done nothing wrong.