10 weeks already!
So how is baby going?
When you lean back, how far to do you recline? Positional feeding is one of the best ways to deal with this. Expressing a little to get the 'worst' of the letdown out of the way first, also. So you already know the basics.
When you say rough start, what's been going on? Any attachment issues? Any possibility of tongue/lip tie?
Sometimes inefficient feeding (caused by ties, for instance) means babies overcompensate and mum ends up with an oversupply and/or fast letdown. And it may also make it harder for them to deal with.
Usually, this sort of thing sorts itself out over the first 2-3 months, but that is not always the case. It's probably worth doing a little extra investigation.