Stanley,
What you explain is normal , I think you will fine that most studies show that certain percent of males have larger glans then the penis shaft .. Now the weak erection at your age could be possible due to several issues such as stress or low T or anxiety or even excess masturbation.. I would not think that swollen glans during arousal is the cause of a weak erection.. my thoughts, ojsam
Hi Penises come in all shapes and sizes ,why not visit your Family Doctor and put your mind at peace , any problems you may have he/she will send you to a Urologist , please take care ,