I have the exact same experience,
@chalup. I haven't found a single fish oil capsule I can take without the same experience.
In the past I've taken krill oil without too much issue, but have heard varying reports about how effective it is.
I think my next attempt might be algae oil.
In the meantime, my genetic report tells me I don't have a problem converting what I need from diet so I'm not as concerned about it as I once was. I eat chia seeds every day and also periodically take flax seed oil and/or EPO.