Food and care for Fuzzy

So in the past few weeks my cat has developed constipation issues. I thought I had found a solution. But on the morning of May 7 she had a very bad morning. While she is acting like herself she is going to need special food and extra attention for awhile. Do to current world circumstances I am on an even tighter budget than usual. Any help you could possibly give whould be greatly appreciated.
As of May 12 she has been going to the bathroom regularly however she has become extremely picky about what she eats. Even more than usual. I found some things she will at least drink but even then its difficult because they are exspensive for what she whould need to consume for nutrients. The only good thing is that she isn't lethargic and for the most part is acting like herself. But if there's any help you can give it whould me the world to me.