Humira is making it worse

I have ulcerative colitis. I have been on mesalamine for almost 2 years and things have usually been under control. But around 3 months ago I got a flare up and doc suggested I switch to humira. It’s been 3 weeks on humira and my life is shit as of rn. I use the wash room 5-6 times a day. Lost some weight. I have never had stomach pain but now I have it and it leads to loose motions too. I have an appointment with my doc soon? But any advice whether anyone faced this at the beginning of humira?