@Okeydokedeva,
I am also not from the UK.
I lived in England for 15 years before I had children. I had worked here all my adult life, I was married to an English man, I had a variety of friends, English ones amongst them, and I was more than used to the English way of life, which I chose and liked.
Yet nothing prepared me for the feelings I had when my first DC was born. Suddenly I found myself having to start from scratch in an environment where once again I felt like a complete outsider. The whole baby experience and then the start of formal education were a minefield for someone not educated in the same culture. The subtleties of human interactions that I could once easily navigate on my own became a source of constant puzzlement and heartache. I suffered for myself and for my DC thinking that I was letting them down.
I internalised every single perceived rejection. The loneliness became unbearable and I developed self-loathing, lack of confidence, and crippling insecurity. My failed attempts to get close to others and develop meaningful relationships were probably due to my own clumsiness, communication differences, and a lack of internal knowledge. I felt so hurt and ashamed that I developed a bitterness towards others, assumed that no one liked me, and took everything personally; and like a self-fulfilling prophecy, as I stopped trying to get close to others, I ended up even more lonely.
If I could give myself any advice as a young foreign mum, it would be to focus on myself via personal growth, because my DC would have also benefitted from it. I wish it had occurred to me at the time to go to counselling. I feel that this is even more relevant in your case having suffered the trauma you have.
This is hard!! I wish you the very best!