There is nothing specifically bipolar in what you are describing. Congratulations on such a significant weight loss! Make sure to exercise not to gain pounds back. You should be ok. You will eventually do fine with girls. Boobs or no boobs, sure a girl might have had other guys before you, but so what? Prior experience does not hurt. I would not aim at stopping to watch porn. I would instead aim at increasing your RL chances by mingling with people, being physically active, reading about interesting things so that you can discuss them with girls, because while complimenting them on their boobs or other assets may be great, you need other conversation topics to carry on.

If you do all of those things, you will be too busy so you won't be watching porn to an excess.

Do not attribute your various reactions to bipolar without good cause. It does not help in any way.