The purpose of investing in bitcoin is to grow it without selling any, no matter the temptation from the market, and that is why it is good to figure out that amount that would not be stressful to you or cause tension to you, and invest with it, so that you can hodli without thinking of selling for a very long period of time. When you are investing, have a bitcoin target and stay focused on achieving it. Although, it might not be easy, but with discipline and sacrifice, and the believe that bitcoin is one of the best assest to invest in for the future. It will be possible.
You have just limited the quantity of your bitcoin, which would have generted a higher profit for you, so what is next, start accumulating now that the price is higher than when you bought those one that you sold...not a wise decision.
Thanks for the clarification but I would also like to add this particular problem of inconsistency is not only tied to newbies because I believe even some persons who have been in the space for some time can still make this error. One thing is to start an investment and the other is to end up with the actual plans you thought of starting with. The points you just dropped are actually the basics to starting a Bitcoin investment because if you don't have an steady means of income where you can atleast cut out a portion that won't affect you if you want to save it as Bitcoin then you might likely just end up using that same Bitcoin you intend to save to solve one or issues that's needs attention just because the planning wasn't certain.