I used to feel the same way in therapy, completely overwhelmed with the amount of crap going on in my head, trying to bring therapists up to speed with 30 years of life with just 1hr per week. Impossible.
It does settle down, that need to verbally vomit up everything. Eventually you settle into a rhythm.

My T has given me 1hr 15min sessions cos the 1hour just wasn't enough and that extra 15 mins just seemed to bring things to a natural closing and i am finding that i leave feeling calmer.

Leah had some good options for you to think about too.