Do you know if you have Hashimoto's thyroiditis? It's the most prevalent cause of hypothyroidism. If you do, you will have to take levo for the rest of your life. There are a few types of "temporary" thyroiditis, but if you were diagnosed 4 years ago, you are beyond temporary.
There is no fix. However, a healthy lifestyle never hurt anything.
Do you have recent thyroid test results to post? If so, please post FREE T3, FREE T4 and TSH and include reference ranges from your own lab report. Inability to lose weight can be a hypo symptom (under medication). Do you have other hypo symptoms?
Levo in any dose shouldn't smell bad. Are you taking Synthroid, Levoxyl, a generic?
A 12.5 mcg increase can make a huge difference, especially if you're close to your ideal dose to begin with.