Healthy pregnancy after miscarriage?

Im a bit overweight at around 200 pounds (hight 5’4) and recently I lost my first pregnancy at five weeks. I’ve been trying to be healthier and walk everyday and eat better while we try to conceive again but I’m terrified it was my fault for not being more fit and that I’ll loose the next pregnancy. Has anyone gone through this before and gone on to have a healthy baby after a miscarriage while being plus sized? I appreciate any encouragement as these last few weeks have been really tough.