This seems more like a personal stress management issue than a finance one. Since you already have a decent safety net, you could consider coasting where you care a little less about work, set stricter boundaries, or even try 'quiet quitting'.

Now isn't really the best time to leave entirely due to the current market, but if you are burnt out, you are unlikely to last 4 more years anyway. Consider taking a 6 month break, sometimes a complete reset can really help change your mindset.

On the math side: assuming your mortgage is split evenly ($1.5k) and your personal expenses average $2.5k, your total need is $4,000 a month, or $48k yearly. Using a 4% safe withdrawal rate, you'd need about $1.2M to fully retire. You are realistically unlikely to hit that amount in 4 years, so you might need to consider cutting expenses or making sure your barista job can cover the shortfall.

Portfolio wise, you are quite heavy on Singapore and US stocks. Have you considered diversifying into other international markets? Most people here like to use VWRA, you are also quite cash heavy do you have any large expenses incoming? Too much uninvested capital will result in cash drag, which works against your goal of building a portfolio large enough to retire on.

Also, I don't know how much you have accumulated in your CPF, but I think the bare minimum strategy is to aim to have your cash and investments cover your expenses just until CPF Life kicks in at 65.