Thank you for your query at DoctorSpring.com.
I understand your concern.
You seem to be under an unhealthy amount of stress. A radical change in diet and strenuous exercise is not the best way forwards given your present condition.
The increased frequency of stools you have had seems to be due to an infection (stomach bug). Generally these are self-limiting with maintenance of electrolytes and hydration required during its course. If your bowel movements have regularized by now, nothing else needs to be done.
How high is your TSH value?
If you are overweight, the thyroid imabalance (high TSH) may be responsible for the weight gain. The excessive fatigue, confusion and even the borderline hypertension may be a result of Hypothyroidism (high TSH and low Thyroid hormones). Depending on your level of TSH, Thyroid hormone supplements should be started.
Meanwhile stick to a healthy, nutritious and a balanced diet. Cut off all the unhealthy high sugar/fat foods and replace with wholesome options. Make sure you are taking the required amount of calories recommended for you.
As regards to exercise, start off with a basic and easy regimen and gradually increase the intensity.
A healthy diet with the required calories and exercise will result in a healthy weight loss as opposed to a low-calorie diet with strenuous exercise which can be harmful.
Please mention your TSH value or upload your report in the follow-up.