Clothes for hot weather? Self conscious about my legs

I have shit self esteem (raised with a religious mum who made me cover up my whole life) that I'm really trying to improve but it's taking time. I also want to lose weight but I currently have a chronic illness where that isn't possible so for now I'm stuck with what I've got.

I've moved to a city for uni and I'm not used to the gross heat here. I'm from a seaside town where even the hottest days have breezes so I've never had this issue before but I'm really struggling with how humid it's getting. It's only 14C which isn't even warm (I'm perfectly comfortable up to 36C usually when travelling etc.) but for some reason it's different in a city and I'm sweating loads and feeling kinda sick with how muggy it is.

The only trousers I own are skinny jeans (I'm tall and they're the only style I can get away with them being a tiny bit short because tall trousers are more expensive and I'm a student) but they're waaaay too hot. I'm super self conscious about my legs though because I'm crazy pale and they're kinda fat (I used to have pretty muscular legs I loved which is how I was fine in shorts on holidays etc. but with my illness I've lost my muscle and I hate it)

What sort of shorts/trousers would suit my legs? I'm super self conscious about the top of my thighs and how my calves look from the front. I don't really like my knees either, or how fat my legs look when I sit down so I don't want anything my fat spills out of when I sit.

I'm just a bit lost with what would look good on me really because it's not a problem I'm used to and I don't have time/energy to run around shops trying out different styles etc.

Thanks :)

(in the photos I'm wearing these board shorts I bought because I loved the pattern but they're too short for me to actually wear out because I'm not comfortable in them so I'm saving them for when I'm healthy and can lose weight)