I'd like to join Sophie_M in welcoming you here, it is a friendly place, with a lot of people who have had had times, something that makes a person more understanding of others.
It would have been hard to try to put down how you are in a first post, and yoy have done a pretty good job of explaining things.
You grew up in a religious household where you parents did not give you the love any child needs, and than had a hard time given by your sisters, who on leaving a religious community in their teens would have had a very hard and confusing time. Not ideal for a young person at all.
You mentioned OCD, childhood trauma, depression and anxiety, and overthinking everything as well as questioning your own behavior to others. Those around you have their opinions, from your boyfriend to your mother.
Really speaking the only way to know what you face is to have a proper medical diagnosis by a professional. Can I suggest you have a long consultation with a GP wiht a view to diagnosis by someone skilled in childhood matters?
Having a degree of certainty can make things easier, it certainly did for me. I had no idea I had PTSD, depression and anxiety to start with and put it all down to me.
One thing that makes me hesitate about your post is your saying you managed to get through depression and anxiety by yourself, even though you still constantly overthink things. I found I simply could not do that, and in time I got worse despite my efforts.
It was only after diagnosis and competent medical help I improved and no longer held myself back from life by overthinking everything. I also no longer wear a mask and behave differently in front of each person -something that simply isolated me and made me feel worthless.
These feelings of uncertainty and also feeling lost are not things you have to be stuck with always, I was a mess and am now pretty good, if I can I'd imagine you can too.
Please feel you can come here and talk anytime