Letrozole

I’ve done Letrozole, HCG and IUI 3 times now and have had no luck 😞. My doctor wants to bring me in for a fourth time to do a baseline and put me on letrozole again, my fiancé and I won’t be home to do an IUI so we will be trying natural. I’m very nervous to go through this process again and be disappointed, but I know their is that chance. Has anyone went through this process 4 times and have luck?