Hello there, I am very new to owning a turtle and I am a bit lost and need help. I recently purchased a female african sideneck turtle and when I first put her in her tank I noticed some issues.
A bit about her!
Her name is Margret, the store said she was around 1-2 years old. I got her on February 19th so she has been in my care for about a month now. She is around 5 inches and I am currently keeping her in a 40 gallon tank, but I am moving her into a larger one very soon! I handle her a lot and she can be very friendly and adventurous but can also get very skiddish at times. She has been moved many times as I live in a dorm room, and with the Corona virus epidemic had to give her a temporary enclosure while I was living somewhere else. She has been rehoused 3 times.
Firstly, she had a hard time swimming up for air, and would resort to going on her tip toes to try and stick her nose up to get air. I've had to lower the water level in fear of her not being able to get up on her own. She is also very lazy, only gets up to walk around a few times and then goes back and hides. She seems to be on a decent sleep schedule but some days she is extra lethargic.
Secondly, she had started eating when I got her, I will admit I may have overfed her on crickets because in the first few weeks I had given her around 6-7. But after that one single feeding she now will not eat. She seemed to only eat when the water level was high, but refused to swim up for air as stated previously. I have had her for about a month now. She will not take to hand feeding as I've tried consistently.
Thirdly, she will not bask. I have never seen her bask a single time since I have gotten her. She sometimes will go right up to the area but never walk onto the land. I fear she may be developing shell rot if this is going to continue.
I wanted to ask for help before I went to a vet because she has eaten before and I believe that it is just something I myself am doing wrong. As a new turtle owner I know that I am doing something wrong. Overall she LOOKS healthy. No mucous in the eyes or nose. Her shell seems a bit off but I am not an expert (why I'm coming here!)
I use Flukers Medley Treat (an assortment of freeze dried meal worms, crickets and shrimp)
Tetra ReptoMin floading food sticks (She RARELY ate these and I have now bought Mazuri pellets as of writing this.)
I also have tried to give her veggies but I have now learned she is more carnivorous.

Here is a picture from the first day I got her

Shell!

Here are some videos of her!
I am very concerned with her and I may be over thinking/reacting but after a month of no changes I have begun to think my concerns are actually for a good reason.