The flat line in my openion is a phase which all should study, take a look on google. i am going through it now since last 4 days. it seems that it can occur in early days and infact at any time period of no PMO duration. It makes you feel depressed, and low energy, tired and sleepy. And you may ask yourself '"why am i not just fapping or watching porn or doing all what has been stopped, it may turn up the situation and may give instant energy and joy " , but its all a lie from your intelligent mind + brain which is now getting detox from dopamine overdose. Now it knows that there will be no free dose of dopamine and for getting reward one needs to do real work ! real intercource with partner, and no imagination and virtual inputs to provide the dopamine. This is a different kind of battle than initial battle with urges. This needs more deep analysis of your minds back of the mind ! catch it while it tries to cheat you and through this survival is possible. believe me if you give in for these thoughts for short gain of Dop. then it will not improve anything. Even while the flat line is going on, the body is rejuvenating and i have noticed that several back pains are vanished which were there in all past years. stamina is increased. understanding level of official, personal matters is enhanced, but mind is trying to trick me into creating hypothetical depression and tiredness.
Yeah, we need such deep thinking and observation to get out and get freedom.