3 week old in pain?

My daughter is 3 weeks old almost 4 and she seems to be in constant pain. When she eats, I can hear what sounds like bubbles in her stomach. She also cries a lot more than before. I give her gripe water and gas drops. She also has a very hard time pooping and when she does it is very thick. Is this normal or should I take her to the doctor? She is also formula fed now because I don't produce anymore breastmilk (Idk why my supply just stopped out of no where). Any ideas on how I can help her? I feel so bad😭