We generally advise couples with no known issues to try for 1 year before taking any treatment. That means it will take even 1 year for some couples to conceive despite of everything being normal.
IUI is better in your case.
You have to understand that success of IUI is only little better than natural pregnancy.
That being said you don’t have to be disheartened by only 2 failed IUI cycles.
You can try IUI again after a break.
Next Steps
Go for the 3rd one. Hope for the best.
Health Tips
Take a break after 3 cycles.
meanwhile consult doctor for Erectile dysfunction.