This is correct, it is impossible to be a long term BTC investor if you do not have a job or a source of income, because even if you plan to hold your BTC for years, you will always have to spend from it for emergencies and to settle basic needs. I have heard there are traders who only trade as their job, i really don't know how they manage to do it, but i feel one should not trade or invest in BTC as their only job, even if you think you are an expert, there would be days profit would not come, and you may have to go borrowing to survive.

Do not feel that selling your BTC is the worst thing you could have done if you sold for an emergency situation, probably you can regret it if you sold because of panic or fud, or to lavish the money on things unimportant.