Chipped molar with yellow / light brown discoloration and ti

I had to use a 'new' dentist due to insurance this August and had a cleaning and checkup with 18 x rays. The visit took four hours (lousy management) AFTER I was in the chair.

Dentist said no cavities and I showed her the pin head sized dots on two teeth up front. They're on the back middle and side not near the gumline. She was totally unconcerned and said cleaning won't remove them and no one else can see them so forget about them.

I'm a good brusher and will check my teeth occasionally with a mirror to make sure there is not gunk left after brushing and flossing. Today I did that and noticed a yellow spot on my last molar sort of on the side right next to where the tooth meets up with a very expensive gold filled porcelain crown. It appears to be two small chips in that spot and closer inspection looks more light brown than yellow.

I'm a super dental phobic and have lost 3 teeth (extractions when they cracked at gum line) after chemo 6 plus years ago.

Could this degree of damage and possible cavity form in 3 months?

I am concerned about the pin head sized dots since those teeth are on the back of #4 and side of #5. If those teeth were lost, I'd be super traumatized.

We no longer have dental insurance and I'm going to call for an appointment to have the molar checked as soon as possible but would appreciate thoughts on all of the above.

I'm 65 and have had bad teeth my whole life yet have worked so hard to keep them healthy! (no soda, no hard candy, no hard chips, no ice chewing).

Diane