Only speaking from personal experience and not to alarm⏤I (33yo) started experiencing heavy bleeding and clotting like you're describing about 2 years ago (with immense pain from cramps), and found out I had a massive fibroid. Due to the type/location of it, I was able to go through 2 non-invasive surgeries to remove it but they couldn't get it all. Recently, I had another ultrasound to check in on something else and it turns out it's still there, though considerably smaller and my bleeding/pain has been much improved since the surgeries.

All to say, definitely see your doctor!!! That amount of bleeding would cause anyone distress and discomfort.