How to have open convo about possible ED with 45M

Seeking advice on how to talk about ED with my partner of 2 years (but known him for about 18 off and on). He doesn’t think he has a problem, but he never stays hard when we are having sex. He’s probaubly average at about 6-7.5 fully erect and has nice girth so even partially erect it can still be enjoyable. But, sometimes it’s just a total turn off, especially when he’s in my ear asking me if I feel that d? I just moan or refuse to say anything, but I really want to scream “actually I don’t!” Or he will say stuff like “ you feel that d getting hard?” and I want to say “Finally!”

Of course I don’t say any of this, but the thought is there and I’m out of the zone. He swears it’s my fault because I’m not wet enough. I drip like a faucet (change the sheets at 1am) when I’m mentally engaged but it’s hard to stay locked in when I’m having these negative thoughts. I never had a problem staying wet with other partners over the years- even before we became exclusive again in the last 2 years (even beyond 40 and 6 yrs post hysterectomy) .

How do I address this without sounding savage or him getting defensive? I’ve tried a before and it didn’t go well. He got real defensive and blamed it on me when I asked if he thought about trying Viagra. We actually had a cooing off spell of several months after that. But we eventually got back together and are now living together. I’m the type of person who chooses silence because my tongue is sharp. I don’t want to hurt his feelings but I can’t consider a lifetime partnership if I’m not 100% satisfied sexually. I’m not at the place in life where sex just doesn’t mean that much to me.