A sister’s concern about salah while traveling and around non-Muslims

As-salamu alaykum! I’ve been feeling a bit nervous about praying in public when I’m traveling alone, since I worry about negative reactions from non-Muslims around me. Sometimes I’d just pray sitting down, like on my bed in a women’s dorm, because there was no private space. But then I learned that the fard prayers should be done standing if you’re able. Do I have to make up all those past prayers I did seated, even though I’ve lost count? Alhamdulillah, I now have a disability and hardly go out, but I’ve recently been able to complete all the arkans of prayer properly. What’s the best way to handle such situations if I travel again in the future?