Its hard to asses things when i dont know what you are doing, but average for new company to get profitable is about 2-3 years, but its not uncommon for it to take +5 years. Especially if its a new thing like the patent makes it sound.

At the four year mark i would recommend you to take a step back and look the processes you do and try to figure out if there is a way to streamline something on it. Its really hard to notice some inefficiences when you have used to do things in that way.

If you have a lot of competion on your business try to figure what is a thing they do poorly and try to do it better. That way the people who are disapointed for that specific thing have good reason to switch to use your product. You dont need to be better than everybody at everything, just find the group of customers that find you as the best fit.

Also if you chance something you do, dont get too stuck in fear of loosing customers. If some change makes you loose 10 customers, but makes you 20 new ones thats not a loss.

If you are operating at loss raising the price is not unreasonable thing to do. For excample if you raise the price 5% you can loose 5% of the customers and make the same profit with 5% less work