Is it hard to become a profitable trader? Yes.
Is trading really worth it? Not sure anymore, there are easier ways to make money.
Is trading stressful? Yes, I know only a handful guys (who's been around for quite a while) that are completly detached from money, can always perfom, execute and keep following their plan no matter what.
Are pro traders out of control party beasts that do drugs and drink to excess? More like low profile, drive Tesla, go to church on Sunday type.
Is trading about indicators, technical or fundamental analysis? If you ever walked on trading floor in proper firm and said 'Long xyz, because MACD is 80 and RSI 45 now, bullish wedge' (you can probably tell I have no idea if numbers are accurate) they would laugh you out of the doors and tell you can go fuck yourself. TA is roughly about support and resistance. FA to have an outlook on marketplace and underlying sentiment.
Can you learn trading from internet? Trading is all about finding niche strategy you can exploit untill it stops working. And these strategies are scarce and if they work, they're kept in secret. All you can learn is TA or get sucked into some trading 'guru' scheme that gets cut from your comissions.
But you want to be trader anyway. Fair enough.
This is chart of my PnL when I first went into business. Prop shop with high commissions and rather bad mentoring. From group of 15 traders who started around the time I did I was the only one who managed to brake through and make some money. Few left early (3-6 months), few gave up later (1-1,5 year), one got axed (after few months for not being a good material for trader), one guy stuck with the firm until it went down and never made a dime. Vast majority of that group were really smart, hardworking guys and they still failed.
Initially you're expected to lose money, you don't know markets, you don't know product. Then you think you're onto something, but you're not so you continue to bleed cash all over the place. You think you have found an edge, but you haven't so you over trade on strategy with negative expected value.
Finally you start to see what's working and if you're lucky more experienced guys let you watch them trade and execute trades on some stock you've never heard about that has some sort of strange, but repeatable inefficiency you can take advantage of. You understand this is what's working. Now this is the point when you might start to understand market dynamics, swing a little bit more and develop skills that are transferable to different product. This is also a stage when you can build up enough conviction to create right plan and execute it. What I mean by that is you've seen enough market moves and patterns over time, so you kinda know what to expect. You build a position in a stock, set right stops (if they trigger you're clearly wrong, not shaken out) and let it play out. If you're confident enough. If not you get out of trade (small stop, bad entry), cut trade short (I made money, I'll go broke by taking profits too quickly) and you're back to square one.
Ultimately you understand harsh truth, good trades are very very very scarce. 95% of trading is just waiting game. Maybe even more. Great trades happen few times a year. Niche strategies or inefficiencies last couple weeks, then people pile up on them and they stop working. But good news, few trades a year is all you really need.
