I've Been Working Out For About 2 -3 Months And

I've been working out for about 2 -3 months and have lost nearly 10 pounds. Over the last couple of weeks, I've been tired so I took a couple of days off. Yesterday was a good workout (pilates) but today I went in feeling good and after a few minutes, had no strength, was sweating profusely, and was pretty punked out...had a high protein breakfast drink before. Felt a little better after some food and water, but it was concerning. Should I contact my physician (type 2 diabetes? hypothyroidism? Just working out and dieting too much?)