The photo is really dark so we can't tell much from that, so here's some general guidance:
1-the foam on the walls is not helping much by itself and it looks like you have nothing extra in the corners(which is where bass builds up) where bass traps should be used(lots of info on the web on this). Grab a pair of tall boom stands, set them up like a big letter "T" behind you and drape moving pads over them to help(everything helps
)
2-after the singer, it starts with the mic, which you don't mention. If you are using a budget mic, your next purchase should probably be a good mic(I can highly recommend the Miktek C7(Keb' Mo' liked it so much, he redid all the vocals on a recording he did several years back after demoing this mic). Do use a pop screen.
3-next in line is the preamp/interface(which you also didn't mention). If the interface is not great, a good preamp would be my next purchase. Either a Neve clone(Warm Audio, Heritage, Vintech, etc) or an API-312(not the 512) or a clone(Warm Audio or Five Fish).
4-(all these could be in a different order
), mic technique! Experiment with the distance between the singer and the mic(closer has more "beef", but this can overshadow the clarity and air you get by backing away 10-14". Once you find where it sounds the best, move the pop screen to keep the singer back that amount all the time(at least until you know the singer has really good mic technique so they move in for soft stuff and back away for loud stuff).
5-there's more, but this is enough for you to digest for now. The specific gear I mention is based solely on my own hands-on use of those products