Trouble Gaining Erection for Jelqing

I am having trouble gaining a semi-erection for jelqing. Once I get one, it usually drops within a minute, so I am stuck jelqing at a very low erection. I am usually turned on quite easily but I just can’t seem to.. What do you think that I should do.

Maybe watch a little porn. Many of the guys need visual stimulation to keep a moderate erection to jelq by.