I'm thinking of dropping out of therapy while in a manic depressive phase and now I use text posts on the internet to talk about my problems to strangers
Does this make you feel better?
I don't want anyone to physically see my big body, just talking online makes me feel good.
In order to be to open up to a therapist or therapy chat, you need to be in a comfortable environment. Talk to your therapist about your issues regarding your body, you may find that they have an ongoing online based therapy already available for similar people.
I don't care
You should not be afraid of judgement, therapy is meant to help you. They only want to see you get better, have you tried opening up about your insecurities to them?