It is hard man, very hard. I struggled for 9 years. I failed 3 startups. I can only hope the best for you.

I went through all the things you say. I stopped doing cold calls. It is the worst thing that happened to me. Very demoralizing and devastating. Sucks my energy and will of live.

Later I fully focused on SEO for the locale market. 6 months later, one day a lady from Sanofi Pharmaceutical called me. They were in hurry to find a local partner for conducting an online proctored exam and somehow I got my first customer within a few business days.

Once you have 1 good customer, you should try to expand over. Here is my advice for this case: https://news.ycombinator.com/item?id=19866334

PS: If you wonder what our product is: https://www.testinvite.com