OK well, since no one else has chimed in, I will give you my input.
Im in my 30s too, so I can understand what you are looking for, and Im not pickin on you, but there really isnt a "steroid for loosing weight". We can go round and round arguing about anabolism, catabolsim, and lean mass gain vs bf% loss, but ideally loosing weight isnt what a steroid is for. Having said that, if your still with me here, there are a number of products that can/may inhibit/slow down muscle wasting and even possibly promote anabolism on limited calorie/cutting protocols. Some things you might consider researching are products like winstrol, primobolan, deca-durabolin, trenbolone, or phs like prostanozol, furzadrol, orastan -a, -e, furzabol, etc. Although there are sufficient arguments against any of these products promoting fat loss, there are also sufficient discussions about using these products while on a "cutting" program. Ideally for your situation, a recomposition would be what you are looking to accomplish. The idea of loosing bodyfat percentage while not loosing/possibly gaining lean muscle is what you really want to do. You may also want to consider seeing another doctor and getting a second opinion on your t4. And you might even consider other drugs like clen, or stim/fatburning stacks instead of steroids if the only thing you have to focus on is the actual scale weight in pounds. Just do yourself a favor and really search the forums here, you may find answers to all your questions, and if not, then just post another question once you have exhausted your searching, you will find that specific questions are more readily addressed than general ones.