Please every woman read this

I need help, I’m a victim of domestic violence and have been for almost 8 years. I never had the courage to walk away before but now I have a 3 month old and I need to save myself and him. I don’t need anyone’s judgement so please I’m only looking for help. I’m a British citizen and I’m in Tunisia, I’m not a resident or anything I’m just here and my baby was born here. I need someone to help me and find out if I can take my baby back to the U.K. I can not carry out these internet searches myself, this app is the only place I can talk. All I was told was that because I’m a British national I can travel back home with the baby but I need to know for sure because people are also saying that he was born in Tunisia so he can’t have a U.K. passport? Please someone help.