Thyroid/ Just hopeless

Anyone else just feel like they can’t lose weight. Genetically, I come from a heavier family (but all those members can lose weight, kind of fluctuate but still can lose.) I feel like I’ve been stuck the 21 years of life I’ve had. I was a full time athlete & still wouldn’t lose much & I wasn’t eating the vest then. Now I work out Atleast 3x a week and eat way better and just feel hopeless. I feel as if my thyroid has something to do with it, so if you have had the same issue, please let me know!! Sorry should’ve added that I have an appointment for bloodwork Wednesday :)