When selecting your one pair, I would suggest that you choose one where at least one of the currencies is of general interest to you. Even if one is a TA-based trader, if adds an extra dimension to one’s analysis when the asset has some real meaning to oneself.
For example, cryptocurrencies have no real underlying substance like with oil or gold and I find them incredibly boring, but other people love them. On the other hand, as a UK ex-pat, I would choose GBPUSD because I still like to follow UK events - and the USD? Well, who doesn’t follow what the US is doing!
It is also worth remembering that no one ever has made even a cent of profit from entering a trade. The only thing that determines whether you win or lose, and by how much, is where you get out! And yet exit strategies seem to be very underrated compared with the amount of energy spent of when and how to enter. Focusing more on your targets and exit strategy may also help reduce the hesitancy and reluctance with actually entering the trade
It is good to have a clear idea before you enter a trade what exactly you are looking for. Is it a fixed number of pips, or an identified zone, or an open-ended trade with a trailing stop, etc. And when that is clear then identify where you are going to get out if it fails.
And journal it! Journal the reasons as well as the levels. Journal the actual P/L per trade and cumulative. and journal whether the trade was according to your rules and if not, why not.
It might also help to imagine that you are trading someone else’s funds (like a prop firm mentality) and that you have to report on all your trades, explain and justify them, and describe the trading environment that you are operating in.
It might sound a bit silly, but build a deep pride in what you are doing. It is no small achievement to get to a consistent profitability level. Trading is quite a lonely business and often it is down to us to pat ourselves on the back, there is no one else gonna do it. So seek value in what you are doing and do it to the best of your ability and with deep commitment to see it through.
Anything that makes it seem more like a professional business with accountability is going to help with discipline and add a lot more interest - even if it is “only” one pair!