If your nose-up attitude goes WAY up the 3~4 degrees then it's a problem of climbing.
It means that you climb too fast to too high a flight level in too little of time.
How you should climb varies from aircraft from aircraft, but let's say you tru to bring to FL350 a full weight 742 (Its the plane I'm more familiar with, after the Concorde

).
V1, Vr... First climbing phase it's done manually. When you clean the wings and up to 10000 feet keep yourself to about 1800 to 2200 fpm (feet per minutes) beginning at 2200 and reaching 12000 feet at 1800.
Over 12000 feet, and depending from weather too, begin to lessen the angle of climb. Remember that you are flying a FULL WEIGHT 742 (in this case)
Keep an eye on the N1 and N2 of the engines and be very attentive to keep an angle of climb that won't strain them. This will allow you to reach the first level of flight (form which you'll step-climb gradually as you burn fuel) of FL330 (NOT FL350).
From there and as (as already said) you burn fuel, you can step climb higher, to FL350, FL370, FL390...
You can't ask to a full weight liner to reach high flight levels form the start, nor can you ask said liner to reach said high flight levels like a rocket. It's a liner, not a Shuttle.

What you need is practice, practice, practice.

If you do all this no problem and still the airliner is exaggeratedly nose-uppity, it could bbe a problem with the flight dynamics of the plane (that you have not specified). Then I can only suggest you to try using some other liner and see what happens.
