IBD and lung issues

I have been suffering from IBD since 10 years. I was diagnosed with ulcerative colitis. I am very weak and at 18 years i weigh only 36 kg. My most blood tests are normal. A few tests like c reactive protein, fibrinogen etc are not within normal range. My question is a few days ago i was walkin when suddenly i felt out of breath and after  a minute or so i got normal. No chest pains. I had many tests to rule out heart probs. I have two questions
1: my c reactive protein level is higher than normal but my symptoms of IBD ( frequent visit to toilet, blood in stool etc) are normal. So if crp is high but i feel bormal would this be considered a flare up.
2: is it true that IBD patients are at an increased risk of blood clots and can face life threatening probs due to these.
Plz help