When repotting, it is best to remove original soil from roots. Looking at your photo, it looks like you just filled new soil around original as you took it out of pot. I would suggest you used pot that is too big. It also should have drainage hole(s) - can't tell if yours does or not. Potting mix needs to be fast draining - easiest way is to mix sifted or rinsed perlite (or pumice if available) with Cactus & Succulent soil, in 1:1 ratio. Plant should be watered when potting mix is almost completely dry - that depends on actual mix, and temperatures and light plant is kept in. It looks like your plant needs more sunlight - it is already etiolating.

Yellowing leaves is not a good sign, usually indicates overwatering. I am not sure what you mean by:..."little growth is going brown"...do you mean new growth? That may or may not be rotting - to be sure, try to post a clear close-up phot of the area in question.

You can go ahead and cut off the inflorescence since it looks like the flowers are spent. Some people will leave them to dry up, other remove them. Your choice.

I agree with everything Rina has said above. Wean your plant into more sun light so it doesn't burn. And when removing all the old soil from the plants roots, sometimes a skewer is helpful.

These are both very helpful. Thank you