You will always get better reception on a beach than in an inland
house. These antenna ideas might help but there is also a reason why
there are so many different opinions on antennas, because what works
for someone doesn't work for someone else.

A big factor is the location of your house. You could have power lines
or other household appliances interfering with SW reception.
Experiment around and I wish you luck.

Did you also try your shortwave on different days or nights?
Propagation can differ greatly from day to day,.

What radio are you using?