Taylor Swift fans expressed concerns for the pop star’s health after she visibly struggled on stage, RadarOnline.com has learned. Swift, 34, is in the thick of her international dates on The Eras Tour and appeared to be fighting off a cold during the first night of her Singapore concert series at National Stadium. Swifties were concerned that the singer needed rest as she was seen coughing throughout her performance. In one TikTok video, the pop star had to take a moment to clear her throat as she coughed during Delicate. Swifties weren’t the only ones worried about her health — even rapper Li…