Sex life has turned bad, how can i stop thinking it's because of me?

We tried to have sex again today but he had to stop, couldn't finish. This keeps happening a lot lately. We hardly try it anymore and when we do he needs to stop after a while. Last time he came inside of me was two weeks ago, the time before that was at least a month. A couple days ago he wanted sex but I wasn't in the mood initially. I tried to clear my mind and all that to get horny. But after 5 mins he told me he no longer wanted sex and the moment had passed. Another time he was pleasuring me, I was enjoying it, thought we could move on to intercourse soon, but he heard someone talking loudly outside and went to look out the window. When he came back he couldn't get hard anymore. He also didn't finish me off, just stopped everything. However, I also gave him a blowjob about a week ago and he came quite quickly.

We talked and he told me it's because of everything that's been going on and there's nothing wrong with me. But I can't help but feel it's because of me. He seems fine otherwise as well and that was the only time he's said that all this is affecting him. Every other time we have spoken about the pandemic, he always said how much he actually enjoys working from home. It's not that I need a lot of sex but I just want to feel close to him again and feel loved. The other day he was suddenly very affectionate and I mentioned he seemed to be in a good mood and I was enjoying it. But that was apparently the wrong thing to say, he hasn't been affectionate since. I mean we still cuddle, but he always seems distracted and I always initiate it.

He does seem invested in the relationship though. When we're on walks (which are allowed) we talk about which buildings we might want to live in in the future and if we walk past estate agents, he takes a look at prices for reference.