I [41M] haven’t proposed to my girlfriend [32F] after dating for almost 10 years. I need advice on how I can save the relationship

Me [41M], and my girlfriend [32F] and I have been dating for 9.5 years. Just over 2 years ago we were on a trip and we went into a jewellery store and got a custom ring made for her. I haven’t proposed yet and she hasn’t seen the completed ring. The jeweller posted it on instagram a few months after making the ring to show his work and that’s the only time she has seen the completed ring. Now she’s calls it “ring of sadness” whenever she brings it up.

A few months ago her sister who lives across the country came to visit us and her boyfriend of less than 2 years proposed on our lawn. Next year they plan to get married at a venue about 5 minutes from our house because they love the area so much. Both sets of their parents will be travelling from out of town and my GFs parents will likely stay at our house. We just bought a house less than a year ago. When we bought the house her mom joked that she would contribute to the purchase of the home if I would marry her daughter, like a dowry.

My girlfriend says although she’s happy for her sister, she’s hurt by the situation because she imagined us getting married at or near that venue. Her mom and sister are visiting us for over a week currently, and yesterday my girlfriend spent the whole day yesterday trapped in the room crying and lied to her family lied saying she’s just depressed (she often gets major depression). In the evening when she told them how she was feeling they said they would fly back to the part of the country where her parents live to continue the vacation. GF apologized and they’re staying to continue the trip.

She has been saying for nearly our entire relationship that I should go to counselling and I’m starting to look into it now. I don’t want to start over in my 40s since I was married once before and since we just bought this house.

She has brought up marriage several times before and since I bought the ring just over 2 years ago. Now she’s saying that if I ever propose she won’t think it’s genuine (says it’ll be to shut her up) and if I don’t propose it’ll continue to hurt her even more. Is there any way I can save the relationship?

TLDR I haven’t proposed after almost 10 years after buying a ring 2 years ago, I’m frozen and need advice in hire to save this relationship.