I don’t always understand when people say they have high expectations of people but then they choose bad partners to be with (and we all did that in life). I’d say it is probably rather low expectation of people.

You having bad tempter or being difficult doesn’t explain or excuse bad treatment of you. It could probably explain if people didn’t want to stick around but not why they would mistreat you. Your partner or maybe he is an ex, which would be good news, treated you badly. I suspect it’s nothing to do with your temper. If it was an issue it would be acceptable for him to leave, but not mistreat you. And if you had high expectations of people you’d not end up with him at all

You likely gravitate towards unhealthy patterns because they are subconsciously familiar to you because of your family of origin. But you could try to get out of this cycle. Have you tried looking for people with similar interests, hobbies? Join social groups (not during pandemics but some might be online), using some type of matchmaking? Are you seeing a therapist?