Hello Augustinto,
There are two problems in your circuit.
1. The offset adjust circuit only works with a very few hundred milli Volts. See my test circuit.
2. Your Opamps require a feedback capacitor of a few ten pico Farads.
The folder with the circuits:
?
It's also very important to use matched transistors.
1. Use matched quad transistors! MAT04, MAT14, THAT300, 2nd choice CA3046, CA3086, CA3127
2. Don't forget decoupling capacitors of > 0.1uF from +V to GND and -V to GND and a real circuit!
Best regards,
Helmut
