Mens aequa. A stable mind, a balanced mind.
Mente aequa - of stable mind.
I think that "Mens aequa" would be´the best choice, since it is of literary and well known origin. The Roman poet Horatius (Horace) wrote the famous ode that has been called "Mens aequa in arduis" (see source below). "A steady mind in tribulation". These words have been a popular motto for many people of Epicurean leanings. But it actually says that one should have a steady mind in times of "giddy joy", too, so i think it's a perfect choice in your case. In Latin and in English translation:
Aequam memento rebus in arduis
seruare mentem, non secus in bonis
ab insolentia temperatam
laetitia, moriture Delli,
seu maestus omni tempore uixeris,
seu te in remoto gramine per dies
festos reclinatum bearis
interiore nota Falerni
"Remember, Dellius, since you must die,
to keep a steady mind in difficult circumstances,
and likewise in good circumstances a mind
free from giddy joy,
whether you'll live always in sorrow,
or whether on holidays you'll stretch out
on a retired, grassy spot and regale yourself with
a choice vintage of Falernian ..."
Latin translators will hardly ever give you a good translation. Writing in Latin is so totally unlike writing in English that most machine generated translations will be completely wrong, especially grammar-wise. If you still want to use a machine translation, ask someone who really knows Latin if the translation is correct, or otherwise it will just look silly.
Happy to see that your medication works! Look at it as that choice Falernian wine...