Thank you for your query at DoctorSpring.com
The fluid you are getting is in response to excitement and has no relation to erection. Just sexual excitement is good enough to produce the fluid rather than erection.
One can lose erection while wearing condom and there is nothing unusual about it. The more hard you shall try to get erection the more difficult it shall become and thus the difficulty you experienced in getting hard erection.
Excess of anything is bad and the same is true for masturbation. You should limit it to 3-4 times per week.
You should take some multivitamin and things shall improve. If they don't improve I shall start you on penile vibratory therapy.
Patient replied :
So the precum is just an indicator that I am sexually attracted to the girl? Also, I thought that the main indicator of being sexually excited is an erection? Do you think that it is just performance anxiety and will this problem go away with time?
Pre ejaculatory fluid is a normal response to sexual excitement.
It does settle over time.
You just need to get past this psychological barrier.