For me 'Woman' is one of the songs on the album most about his relationship with Louis - he doesn't want to see Louis with the women has to publicly be with and it's agonising for him when he does. 'He's right where I should be' - ie Harry is saying he should always be by his side but instead you (the person to whom he is speaking) is instead. Part 1
‘Apologies are never going to fix this’ - I get the feeling so many people have said to them 'sorry but it has to be this way’, 'sorry but she had to hold his hand/be with him at that event (even though it should have been you)’ (and to some extent he understands that) but apologies don’t make it any less horrifyingly sad for them. Part 2
The last part 'this thing upon me howls like a beast, you flower you feast’ kills me. It feels an animalistic anguished cry - he watches whilst the person (who is allowed to publicly be at Louis’ side - Woman) flourishes at their expense. Incredible songwriting in my opinion. Part 3/3 thanks for reading.