I'm going to guess that you're not in the leaving them to cry camp (neither was I),
To me, your baby sounds within the range of normal for his age. My first was a 'better' sleeper than this, my second 'worse'. Both have since gone through good and bad phases with bed & sleep. Weaning made no difference here, and my second got worse in the months following weaning (3-4hr stretches to hourly for a long time).
The only suggestion that I'd make is to make a decision rather than being led into anything automatically. I found it helped psychologically.
By this I mean you dont HAVE to give up your evening and have a baby on the boob - it's a decision you have made to be baby/comfort led. So, take pride that you are being that comfort, and do what can you do to make it as bearable as possible. Screen upstairs, upstairs, audiobooks etc.
Or decide to try to change things, and feel proud of making that decision too.
This stage wont last forever. It'll be replaced by others - some easier, some honestly harder, but they eventually pass.
At 3+5 I often have evenings, but sometimes I still don't. I go to bed late to maximize them, as it's usually 8-9 before both are down. But there have previously been periods where they'd be asleep at 7.30 (and sleep through). Sleep isnt linear, and no stage lasts forever.
Your sound like your doing a great job.