Shez,

I understand this. I can relate.

This is 'splitting'.

We BPDs do this often enough. We can't integrate. Our emotions about a particular person, event, thing or situation are not cohesive. They don't follow a linear path. We can not thread the emotions together:

Our perception: If I am not good I am bad. If I am unhappy I am sad. If they are not GOOD then they are BAD! If they don't love me then they hate me. If they don't agree with me then they adamantly disagree with me. If I am not pleased with them I must be displeased.
Reality: I can do bad things but that doesn't make me a bad person. I have various emotions ranging from happy to sad with many in between. Other people are fallible, they are not perfect and I can't expect them to be good all the time. A person can love me and still disagree with me. etc.

From wiki
"Splitting creates instability in relationships, because one person can be viewed as either personified virtue or personified vice at different times, depending on whether he or she gratifies the subject's needs or frustrates them. This along with similar oscillations in the experience and appraisal of the self lead to chaotic and unstable relationship patterns, identity diffusion, and other-directed mood swings. ...
The borderline personality is not able to integrate the good and bad images of both self and others, so that people who suffer from borderline personality disorder have a bad representation which dominates the good representation."

I am fully convinced it is developmental (along with the entire Borderline pathology)...we didn't create essential pathways needed when our fragile minds were still developing! It's not our fault and we can still open those pathways to ourselves it just takes a lot of work and patience. So first, be very patient with yourself shez, try not to beat yourself up about having these thoughts.

What if you tried writing down things about your bf that you know to be true? ie. he is good with the kids, he makes me laugh, he knows how to cook really well etc. I find that if we can remember the other person's good qualities, especially when splitting takes place it can help us begin to form a cohesive 'full' concept of that person.
We can begin to see a person (or ourselves) on a whole spectrum of differing moods, actions, beliefs rather than on one side of the spectrum and then the other.
Your bf can't be annoying ALL the time can he? He must have some good qualities to remember. Make a list of those things, pull them out when the negative side of the splitting takes place. What do you love about him?

I can certainly relate, my SO gets on my nerves and I really have to work at discerning between good and bad and integrating it all into one person, I feel this is a key aspect that DBT addresses. With mindfulness we can begin to integrate things into a more linear pattern. With our very segmented and temporal way of thinking we jump all over the place from one extreme to the next (I find myself doing this often enough). I can understand how it can be frustrating and overwhelming.

We are running in 'emotion mind' when we want to be running in 'wise mind' we can not be wise or rational when we are running on our emotions (ie. annoyance, anger, frustrationg) we can only be rational when we are mindful and truly aware of what we are feeling without judgement.

Try this worksheet.
http://www.dbtselfhelp.com/html/mind..._emotions.html
On the one side write your current perceptions --what is he doing that pisses me off? why is he doing it? ie. interpretation: he is leaving dishes on the table to irritate me on purpose, if I talk about it we will break up vs. mindfulness: when dishes are left there I feel overwhelmed, he is not doing it on purpose, he is just forgetful. If I talk about it using interpersonal effectiveness we can begin to communicate better and change our current situation.

Also, DBT suggests when communicating with others to use the acronym GIVE:
Gentle- Be open, patient, generous with time and attention, talk with someone the way you would want to be talked to.
Interest- Show interest in what they have to say, ask questions.
Validate- Just as we want to be validated, so do others, repeat parts of what they say to show that you're listening. Validating doesn't mean agreeing.
Easy manner- Be light, easy, smile, make jokes. Is this a serious thing anyway? Am I putting too much emphasis on it? Take it easy, we'll laugh about it later.

You are definitely not alone in this shez..I really do understand what you're feeling. It's frustrating to think our minds can be so chaotic and extreme. Just remember that you don't have to make any decisions right now, especially not while you're emotional. I know it often feels like one blow up with a SO can appear as if the whole relationship is going down the pipes...but mindfulness helps us integrate those things too. Keep talking. Sending much love your way.