SICK 4 WEEK OLD

My son has been congested and sneezing and coughing for about a week now , I called his doctor and spoke with a nurse and I was told that if he doesn’t have a fever he just has a cold and to use saline drops and a humidifier and the bulb to clean out his nose I did that for a few days and no progress so then I took him to be seen in the office and they told me the same thing and I even put him in the shower with me so he could get some steam and still nothing , today I went to clean his nose out and his snot is yellow correct me if I’m wrong but that means something is wrong he’s fighting an infection or something . I lay him to sleep and he sounds like he can’t breath and is gasping for air , I have to suction his nose out and put saline drops just for him to get at least a nap in . Should I take him to the children’s hospital can someone help me please I’m going crazy 😢 and now I’m not feeling well