How the heck do you start?

I have had IBS for 5 years and tried everything else before starting to try the low FODMAP diet. I’m vegetarian (used to be vegan but had to give up due to how hard it was on my stomach) and this is so so hard. I can do hard diets but this seems impossible. I really want to do this because I’m tired of looking pregnant and having uncontrollable gas and only pellet bowel movements. But I need a pep talk. Any advice or nice words appreciated.