Just keep looking up high quality surveys on different loneliness related topics until you are convinced. There are a lot of different ways to ask it. They all point in the same direction.
Even the surveys you sent already suggest that people who live with spouses are much less lonely, which seems to be the opposite of your claim.
Frankly, your claim sounds so insane to me (someone who has a lot of choice in how I spend my time, enjoys the company of others often, and is not lonely) that I think it would require extraordinary evidence to convince me.