So.... a few days ago, my EQ score increased +32 pts. Putting me at a whopping 639... I was sooooo surprised and happy. Then, yesterday, I decided to go to Cap1 prequalified site.... Platinum Classic and Quicksilver1 showed. I went for the Platinum (no AF 1st year and only $19 after) Well I was instantly Approved! (a Toy limit, but I'll take it for now!) My first 'unsecured' card in only 3 months since I've been here.... I got the itch.... UGH!!!!!!! Kicking myself hard today... I, under the 'high' of being approved for one, applied for 2 MORE!!! Barclays 7-10 day msg... (prob denied) and Quicksilver1 (I figured why not?!!! DENIED). I'm so mad at myself today because of the damage I've probably caused to my scores with all the HP's... Hopefully I can recover soon. I'm satisfied with what I have and I'll just have to take a back seat and work it for all it's worth at this point. I won't apply for anything else for a very long long time. Lesson Learned (the hard way as usual) 
Well you do have a point about the amount of Inquiry's... However, My EX file must be thin, because it just got bumped +18 pts. So sometimes I guess they can be helpful.
I wouldn't be suprised if this didn't happen to most people working towards improving their credit. It's normal to want to be rewarded for hard work. I'm guilty as well. Got approved for a QS1, Cap1 platinum and a home depot for 500$. After I got some things removed from my credit plus the bump from having the new cards I got a little carried away and tried the soft pull pre-approval sites for AMEX and Discovery. Of course they said go for it, which I did, and was denied after a full hard pull check. Oh well, like you I learned and am currently happy with growing what I have, but I still get that urge every time my scores go up
That happened to me at first. I was super shocked that I was approved for any credit whatsoever, after a few years of being in the desert, so to speak.
I applied for Cap1 QS1 and it wasn't immediately approved, but that's because they needed me to verify my identity.
A few months later, I applied for the Capital One Classic Platinum and it immediately approved me.
Now, another three months later, I applied for the Delta SkyMiles Gold AMEX and it immediately approved me.
It does get better. 
It's just hard sometimes.
I think just about everyone makes that mistake at some point... it feels so good to see numbers rising and once you get one approval you start feeling like the sky's the limit! And it is! Hahaha just not for awhile.
I agree with everyone else, inquiries don't hurt you as much as you think, and once you make the mistake once it'll probably be months before you try again. At least you got an approval! And, in some ways, there can be a silver lining to not getting another 2 approvals. Having that many new accounts right now can hurt your Age of Accounts. I know it doesn't hurt a lot, but it's the small comfort I tell myself about why not having more is good
Keep gardening, you'll see the fruits of your labor before you know it!