'09 328i - Advice - Transmission "slipping"

I have a 2009 328i sedan with a manual transmission. I'm at 180,000 km (~111k miles). Nearly all highway driving.

Very recently I started noticing that in 3rd, 4th, 5th and 6th the transmission is slipping. When I'm in gear and between 2000-3000 rpm if I push the gas down with any force the transmission "slips" or "bucks". When I'm at low rpms I have to accelerate slowly to avoid this happening. It very rarely does this in 2nd and never in 1st. Its been getting worse for a couple weeks now.

I gear down religiously and suspect this could have contributed to the wear on the gears....thoughts?

I'm not mechanically inclined but suspect either my transmission or clutch is in need of repair/replacement.

Any help is appreciated.

Wrong section, the E90 section would better serve you.