BA8BAK Unlike UV antennas, shortwave antennas don't necessarily require being mounted high up. While mounting them high is certainly better, many people in urban areas won't have the space to do so. Even extending a fishing rod out of a window can sometimes work (of course, this is an extreme case, and the actual results will depend on the mode and whether you're using voice or weak signal modes like FT8 or CW).
First, don't worry about how to fix the antenna; instead, try out some common antenna types (such as GP, feed-point, DP, and positive V antennas) first.