Drool rash

My 3 month old has been showing signs of teething for weeks now. He is almost four months. He’s constantly been chewing and sucking on his hands. He drools so much that he soaks through anything so fast. We bought him a teether mitt to help but now he has a rash that we are positive is from his drool. We have tried everything from wiping his face and chest with water, using Aveeno lotion for dryness, we put mutli purpose destin and Vaseline on his chest, but he just drools so much that I feel like it’s just getting worse. We are scheduling an appointment with the doctor this week but I feel so bad because his neck, chest, and face are red and chapped. Has anyone dealt with this and know what we could try? He hasn’t had a reaction to destin or aveeno before so I’m not sure if they are making it worse?