It would have been problematic if you wanted to invest in bitcoin aggressively with the money you are supposed to use to solve your expenses, but since you want to use all your discretionary income to invest in bitcoin, I don't have any problem with your decision, and it is even good for you to use all your discretionary income to frontload your bitcoin investment since you are no coiner or low coiner rather than using it to live a lavish lifestyle that will expose you to sell your bitcoin investment too early.
No, I don't think that using your discretionary income to live a lavish lifestyle will compel you to sell too early, what actually makes you to sell prematurely is when you fall to put your emergency and reserve funds in place, and then emergency struck, that's what makes you sell too early even when it's not your intention.
Then as for the aspect of investing all your discretionary income, though it's not terribly bad, but I sees it as more problematic to you because their are so many other things you wouldn't be able to do due to the fact that you don't have the spare cash to available again. To me Bitcoin investment is something you do base on your own financial strength, not by stretching your finances that might be problematic in the future if proper money management skills is not being utilized.
I don't see anything wrong with the bolded word, Nightwatchmare was only giving some advise that instead of your Discretionary lavish lifestyle though there is nothing wrong enjoying your self even while making some bitcoin purchases but instead of spending it unnecessarily that it will be better to be use to buy more bitcoin and i found reasons in it, it's better to keep buying bitcoin gradually than buying and not buying again for a long time because of insufficient discretionary to make bitcoin purchases.