to answer somehow 'heretically':
reduce reading of internetsites of any kind at all, but focus more on real books.
in the long term you'll enjoy it way more. for several reasons i don't want to stress all here.
I observed the same on me, and it bothered me for a long time.
besides the fact that todays society is way less capable to focus on long texts (spoken or read) but trained to constantly consume a permanent stream of quick, short, easy pieces,
there may some points you can actually do yourself.
check the way you speak. intelligent people tend to speak like written texts, trying to perfectly formulate their speech, to be correct, not to be misunderstood, to respect complex correlations...thus producing complex monologues, strenous to follow. combined with monotonous sound it can be really narcotic to listeners.
natural language is not for that. natural language is for dialogues.
also "nerds" tend to focus on matter-of-fact texts, only, while interhuman communication is way more, happens on way more levels. don't underestimate the non-verbal communication! it happens, if talkers are aware of it, want to, or not.
respect your audiance; don't underestimate them. some tend to always explain elaborated every single detail for no reason. this not only produces superfluid text but make your listeners feel you think they're stupid. let them ask if they don't understand. try to involve them into your thoughts, to do the talking more interacting.
is what you're going to tell as important or fascinating to others as it's for you? also my wive fades out often when I talk; I am highly interested in technical stuff. she being from liberal arts is not. but when the topic is real important like relationship stuff she's always full online, and I benefit a lot about the things where she's more improved as me.
besides to simplify your speech, you may loosen it up, consider to put some - few, light - entertainment elements in, maybe even a joke - even in experts talks.
the lesser one speaks, the more focus he or she gets if she or he says something.
this can be elaborated way longer - but this is neither the place, nor right medium to do it.
so, the most important point:
don't take it personal, and above all not too serious.
if you start to think it's because people think less of you, disrespect, or reject you, this may lead into depression.
and it's wrong.
most of the times it's simply people don't want to listen - to anybody.
most people don't want to listen, they want to talk.
for the rest:
even simple rethoric workshops help a lot.
check for evening classes or similar.