Lost on what I should think 😞

I have had sore breast for the last two months and have done pregnancy test and even got some from the doctor and they all come up negative. I have been gaining weight every month  and i now go to the doctor every month to have my weight checked and it keeps going up no matter how much I exercise and diet. I have also had a heighten sense of smell to onions when the use to not both me any. Any advise would help. I'm beginning to lose faith in getting pregnant been trying for over a year and then my syptoms are getting worse 😞😞😞