See I was thinking about this yesterday evening. Lou obviously does have issues with his self image, but I started musing about the reasoning behind this. He's posted many times about his 'place' in the furry community and his purpose- along with how his follower count is dropping. Now whilst this could be a fear of people leaving him, I also feel it's something to do with him feeling like he deserves to be seen in a lot higher esteem than others. He is constantly shaming other people, even lying about his identity for more and more attention and asspats. He definitely sees himself as better than everyone and wants everyone to validate that he is this great person.
As you may already know, narcissistic traits are rooted in low self esteem and self hatred- those with NPD seek validation from everyone around them that they are this amazing person because inside they have very little confidence in themselves. BPD is actually a lot more deep in the way that those with it suffer from an inability to manage the logical side of their thinking Vs the emotional side of things. They may understand that, logically, someone is not abandoning them, but the emotional pain and fear is so strong that they can't ignore it.
Lou makes all these public statements begging for people not to leave him, but he never seems to care that much on an individual level about his friends. Undertale LARPer and the other asspatters never seem to get a lot of actual love from Lou. Its all very superficial and most of the time the stuff he says just reeks of "give me more praise" instead of actual appreciation for these people who seem to genuinely care about him.
And then we come to the suicide baiting. Now something that bothers me with Lou is how everything he does is so public. He doesn't seem to ever seek attention from people on an individual level, other than that one badger dude who never replies to him. With BPD, sufferers usually have a "favourite person" who they fixate on getting affection from. This person may change very quickly, but usually there is one person at any given time who is the one figure in their lives that they are specifically worried about being abandoned by. With Lou, he always baits and cries about things in a public way to get the most amount of attention from as many people as possible. BPD sufferers can survive on the attention of only one person, they can cut everyone else out of their life as long as this one person loves them. On the flip side, they could have all the attention in the world from a bunch of other people, but if this one person was to 'abandon' them in some way it's game over.
Basically what I get from Lou is he wants to be this great, popular figure in the furry community that gets love and attention from everyone in droves. He sees himself as deserving of this and goes out of his way to make sure he lets everyone know that he is some poor, suffering person who is way better than any of those disgusting nazi republicans. He will put everyone around himself down to lift himself up. He baits, but never acts on anything. BPD has one of the highest suicide rates of all mental health conditions, because the mood swings and emotional dysregulation cause actual, genuine depression.