I've tried everything I can possibly think of to improve my computer's performance, and it seems to be getting slower every day.

Before I begin, let me post my system specs real quick:

Hardware Overview:

Model Name: MacBook

Model Identifier: MacBook5,1

Processor Name: Intel Core 2 Duo

Processor Speed: 2 GHz

Number of Processors: 1

Total Number of Cores: 2

L2 Cache: 3 MB

Memory: 4 GB

Bus Speed: 1.07 GHz

Boot ROM Version: MB51.007D.B03

SMC Version (system): 1.32f8

Serial Number (system): W8******1B0

Hardware UUID: 90146DFB-93C5-5699-AB59-05403BEC071C

Sudden Motion Sensor:

State: Enabled

Storage:

Available: 61.79 GB (61,793,218,560 bytes)

Capacity: 255.2 GB (255,200,755,712 bytes)

Mount Point: /

File System: Journaled HFS+

Writable: Yes

Ignore Ownership: No

BSD Name: disk0s2

Volume UUID: 2DA6DBEC-85AD-3415-81FA-B6979712E3E5

Physical Drive:

Media Name: V4-CT256V4SSD2 Media

Medium Type: SSD

Protocol: SATA

Internal: Yes

Partition Map Type: GPT (GUID Partition Table)

S.M.A.R.T. Status: Verified

So, a while ago I decided to get a SSD and upgrade to 4GB of RAM when I was still using Snow Leopard. Great investment, totally worth it. Well, for a while. Boot times were good at first. But they got sluggish. So of course I decided to upgrade to Mountain Lion because that would speed up my mac, right? Wrong. It takes my computer ten seconds from the time I push the power button to respond and begin booting. It takes anywhere from one to two and a half minutes to get to the login screen. On the login screen it won't respond to any input from keyboard, trackpad, or mouse for ten seconds more. When I type in my password, it's another thirty seconds to a minute before the spinning beach ball of death disappears and what should be my desktop appears. Instead I'm greeted by my desktop picture and nothing else. One to one and a half minutes later, my desktop, dock, and menu bar are all there in front of me. But we're not out of the woods yet. It takes about two or three more minutes before my computer becomes even remotely usable- if I just start clicking I'll get the beach ball of death and have to wait longer, watching my once-swift Google Chrome browser bounce endlessly up and down, never opening.

TL;DR: It takes way too long for my computer to start up given its specifications.

You might be poised at your keyboard right now, telling me to repair disk permissions, clear caches, reset PRAM and SMC, etc... but I've already done that. I have about 75GB free space on my solid state drive, so that's not an issue. I've used Onyx and CleanMyMac2 to clean up anything that could be causing the problem, and it hasn't fixed slow boot times and general sluggishness.

I've scoured the forums far and wide to find the answer that will transform my computer into the speed-demon it once was. That is why I have turned to you, dear internet, to aid me in my quest.

I'm not a digital dummy- I can follow just about any advice you give me if you're clear enough in explaining steps required. The OP in almost every thread I've visited thus far was clueless and simply needed routine maintenace or a hardware upgrade to fix the problem, and I know that can't be the issue... so what can?

(PS I did select the SSD as my startup disk after installing it)

<Edited By Host>