If you'll indulge me a few observations - in no particular order:
I note in you gear list, you don't cite what microphone you have. Not all microphones are the equal, just like instruments. Different mics of different quality (and price tags to match) produce differing results. Don't expect that 15 quid omni from Tandy or the freebee you got with your PC to sound like a 800 pound large diaphram cardoid condenser on a shock mount.
One reads that "pro" sound engineers have cupboards full of mics and choose one that is appropriate for the person they are recording, the style of the music, the "sound" they are trying to create in the track and of course sometimes just plain old personal preference.
You don't mention headphones: If you play a CD over your stereo, set up a mic in front of it, sing & record the result, you'll get "spill" from the playback track into the recorded vocals which complicates subsequent mixing. If poss. record in a silent room, put the playback into cans, plus your voice (a bit of reverb on the vox helps) & record the vox "dry" then start playing with fx etc. later during the "mixing" stage.
However, I struggle to sing in key in cans, so I do the "one ear in one ear out" verion which helps me, though I got better with both ears "in" the cans with practise.
You mention that there's "not much echo/reverb" added to things you've heard. Bang on - but it almost certainly WILL be there, most beginners (moi included) add far too much fx at first, before realising that "less is more." Once you get used to listening for it, you notice this much more in "real" records (and spoil you're enjoyment of them forever - be warned.)
Put your mike on a stand, don't hold it. If no stand, tape it to something, dangle it from something, whatever, just don't hold it.
Sing standing up.
If you stand really close to mic (like eating it as rappers and metal heads tend to) you get a "bass effect" in that bass levels are higher. Better to stand a bit further away (hence, use a stand) or roll off the bass levels a bit on the mixer. (The latter can also help the vox "sit" into the mix a bit better. Sounds strange in isolation when you "solo" it, but works in the overall mix.)
Don't drink citrous drinks while recording (think what happens to your mouth when you suck on a lemon.)
Don't record & mix on the same day. Record one day, concentrate on performance, singing in key etc. Leave it to another day to do the final mixing to make it "sound" good.
"P" and "K" sounds can "pop" the mic and the levels, watch out for that.
Last trick is for multi-part vox, like harmonies. If a lyric ends in hard sound such as the aforementions p/k sounds, you can get a kind of "machine gun" effect with three or four parts. A trick is to have one person (usually the lead) sing the hard sound and the others omit it. eg, if the line ends on the word "track", lead vox sings "hears my track" the rest sing "hears my tra."
Mind you, my voice is pretty rotten, so take the ultimate mixing decision and just don't bother to sing at all if I can help it. (At least, not when anyone is listning.)