Whats wrong with my cat!?

Hello all, my cat Ember is a manx. She is about 6 months old. She recently revieved her last 3 way shot. She has been lethargic and tired. She sleeps all day and all night with the exception of me lifting her off of my bed and setting her into the litter box and then she goes pee and slowly walks over to the food bowl. She had been eating had food but kind of lost interest so I started giving her wet food. She doesent eat a whole ton but she eats. She drinks lots of water also. My bed has a soft blanket on it that she likes, she kneeds it and purrs and sometimes purrs when I pet her. Hey purr sounds a little horse every once in a while and sometimes she sniffles a little. She also hasn't gone poop since she started like this which was about 3 to 4 days ago. I am so worried about her. Please if you have any suggestions or any advice I would love to hear it!

Thank you, NugxNug

I would contact your vet.  The longer you delay the more dangerous and $$$ it could become, quicker intervention usually saves a LOT of $$

She also is a bit more active. I hadn't seen her leave my bed yet and this morning she was up in the cubby above my computer. I will see how she is through the day. Also even before she got sick when she is outside she eats dirt, mud, and drinks muddy water. Even though she has fresh water close by. Maybe she is lacking some minerals?

Unlikely. Sounds like vaccine reaction.