Pregnancy concerns

I’m currently 4 weeks and 3 days according to my what to expect app. I haven’t been to the doctor yet because they don’t want me to come in until May 25th which is fine but I’m just so worried I’m going to miscarry. I know I can’t do this to myself but I’m not the healthiest. I’m overweight, I weigh about 280, I have high blood pressure which I’m on medication for, and I have hypothyroidism which I also take medicine for. This is my first baby and I’m so excited but part of me feels like I can’t enjoy it because I’m so worried something bad is going to happen. Has anyone had a healthy, smooth pregnancy with the same health issues? I just need some reassurance from people who have been through this. How do you stop worrying about that stuff?