Make It Go Away! Itchy Mosquito Bite-like Bumps On Legs?

At first it started with two that were just like mosquito bites around the front of my ankle. But they itched a little more than mosquito bites.
One of them left a red spot (maybe because of all the scratching) that is now pretty much a scar (it’s been 3-4days now). Over the next two days there’s way more which itch like crazy and leave a red/pink spot on my right calf (1 more), right thigh (4), right butt cheek (3), left foot (2), right foot (4).
I looked up chiggers, flea bites, bed bug bites, fire ant bites, sand flea bites, allergies, hives but none of them look quite like what I have.
It’s hard to know what I have because in the past 2 weeks I have:
-been to the beach alot (3-4 times)
-been in a very grassy environment (i just started at a very nature-prominent uni ie bushes, pond, trees, lots of grass)
-looked after someone elses’ dog for 3 weeks but returned him 2 weeks ago (he scratched himself alot at the end)
-both i and my sister have it (but neither parents or her bf have it)
-occurs mostly over night but my sheets are white and i’m quite clean and can’t find any bugs in my bed
-had a flea bite before and what i’m getting are bigger than the little itchy flea bites.
They usually pop up in twos/threes in the same area and are so bad now that i’m too emabressed to wear shorts or thongs anymore. It looks like i am getting diseased legs.