I've Taken Loratadine (Claritin) 10mg For A Month 1 Each

I've taken loratadine (Claritin) 10mg for a month 1 each day but ran out after that month. After I ran out I didn't get to refill my prescription and after 6 days or so I started feeling really bad like ,off balance,heavy headed,pains in parts of My head,etc.. I'm guessing it's because I abruptly stopped taking the medicine and my bodies reacting weird to it so maybe all of my sinus issues are coming back ? I'm not sure someone help.