dealing with trolls

I am brand new to this (signed up yesterday ) but I have done a lot of coaching for the past 15 yrs. I am at a happy place but I got derailed a few weeks ago (about 2 months). I am an MD and chiropractor (my main job) and I am specialised in Plant based nutrition, I have a blog, I write for magazines, and I give conferences on the subject.
This summer I got contacted by a dietician who basically tells me I am too extreme and that I should not tell people to stop eating meat (which is actually not what I do, I give scientific, independent, quality information to people who want to transition to an optimal plant based diet. He is always pretending to be nice, I only emailed him back once because I don’t want to waste my time (he is obviously not reading my posts and especially not the resources I cite).
Now he even created a page on FB telling people how I am biased by my ideology, that I am not qualified to give nutrition advice (I have all the credentials needed, and actually a lot more than him, plus I am an MD, so from that standpoint, human health is my business, but anyway) etc etc…
Anyway. Now my question, or problem … I have a hard time finding the will and strength to expose myself again. If I am not visible I can’t be attacked, basically is my feeling,
I usually am happy to write articles, to write about controversies about plant based nutrition, responding to articles with good science, but since his last email, I feel deflated, tired and a bit depressed.
I know I shouldn’t care, I know haters are the norm once you speak up, and when your opinion is counter current, of course there will be some resistance (a lot, if we talk plant based nutrition and veganism). I’ve had a lot of people not agreeing with me everywhere I write, but this one is really getting to me. I really wonder why he has it in for me so bad. I am not famous, I am not making money with my nutrition website (well, very little, I just sell an e book here and there, and some coaching… and by the way I have a new book that only needs me to add one recipe to be published and I havent done it since this summer)
We have moved into a new home 2 months ago, there was a lot of work to be done, so it’s been hectic in terms of physical and emotional efforts. (I am super happy about the home, by the way, but it’s a lot of work on top of everything I already have)… maybe I am also tired because of that, I don’t know.
Please help me find the will to speak up for those who need to hear my message.
(I do all of it in French, I live in Switzerland… and there is a real need for reliable plant based nutrition information in French)
thank you so much, and sorry about the lengthy email… The title was probably sufficient 😉