Sorry this might be poorly wrote I'm tired and on a phone

I've been recently doing self evaluation and researching more about myself and how I perceive things. I wasn't trying to find a diagnosis but I discovered almost everything I researched about myself led me to articles on bpd. And I found I do something *similar* to splitting but I haven't seen it explained like this anywhere.

I can't get mad at other people, I only become frustrated with myself. It's very difficult for me to feel anger towards someone, let alone think I hate them. But I can become very angry / violent with myself very easily. 

So in regards to splitting, while in one moment I will think my SO is perfect and caring, then something will happen and the next moment I'm just painfully empty inside and I've convinced myself they have never loved me and I'm just being used and I deserve it. And all I can do is shutdown, retreat inside myself, and wonder "why don't they love me"

This is probably something different and I should look elsewhere for answers but if you have any insights as to what this might be please let me know.