Yes.
I have severe anxiety that comes and goes. The frustrating thing is that it is completely unrelated to outer stimuli and just random chemistry.
I already have one diagnose and have an ongoing investigation for a second one. Due to Internet stigma, I will refrain from disclosing which they are.
The problems I have, however, are quite deep reaching in so far as that they have a massive effect of who I am as a person and how I feel and act toward my surroundings.
I have periods where I appear to be a manipulative douche-bag playing my surroundings against each other and fear of allowing anyone to see the real me, resulting in alienating people I genuinely care about.
And other times (where I am and have been for a fair few months), where I am just a complete wreck with anxiety, my abandonment issues arise, I stop functioning at all and lose the little social skills I have. The only bright side with these periods is that my creative side gets really augmented. Otherwise I just sit in a corner, rocking back and forth while being scared of everything.
And other times again, I'm neuronorm-functional. Which makes me curious, sociable and wanting to talk with anyone under the sun and just want everyone to love one another.
I don't have split personality disorders or similarly, I just have personality instability.
It's really awful to be around me since I'm a total dick to people, but it's even worse to be inside it and seeing it all happen. I loathe the person that I am and can be.
And beyond that, I also have obsessive compulsive behaviours which manifests themselves in different ways.
I'm not on any kind of medication, but I wish there were some out there to just kill all emotion and make me your run-of-the-mill drone. Alas, as I am in contact with psychiatry now, I embrace whatever they will feel will be best for me (with a source critical mind of course), medical or therapeutical. I am not at the stage of treatment right now.