I will explain the best i can ,i hope someone understands :)

I can't think of why you would hook it up that way. That's certainly not how your supposed to use what you have. That is an impedance mismatch nightmare. 
First , the electric guitar needs a proper electric guitar matched preamp.. You have that on your guitar amp,, so that's is the best place to plug your guitar into. 
Second, a guitar amp makes a pretty bad studio monitor which is what you seem to be proposing. 
So you plug the guitar into the amp and record that. 
To record the sound from the amp depends on the amps output options. If it has a speaker emulated output or a DI etc. 
If not you will have to mike it which is ultimately the best sounding option. 
If it is not possible to use the amp for your pre amp then you need to buy a stand alone pre amp or use an audio interface that has that option. 
 

Have you considered using an analog mixer to route your signals?
 
I have an older version of this Mackie 1202 mixer that used to be very handy for taking mic, guitar, and instrument inputs, and routing them to my PC audio interface.  I could send the audio back to the mixer from the PC and route it to my speakers for monitoring via the mixer.
 
There are multiple ways to set this up, but one of them would surely work for you.  This unit has Main, Tape, and Control Room outputs, as well as an Alt bus, sends, returns, channel inserts, etc.  Very flexible!
 
Mackie 1202VLZ4 Mixer
https://www.sweetwater.com/store/detail/1202VLZ4

I have a two device solution which gets around connection problems. A separate headphone amplifier which is connected to my soundcard. The headamp connects to my speakers. Either way you need a splitter or some sort of intermediate device between your source and output.
 

abacab
Have you considered using an analog mixer to route your signals?
 
I have an older version of this Mackie 1202 mixer that used to be very handy for taking mic, guitar, and instrument inputs, and routing them to my PC audio interface.  I could send the audio back to the mixer from the PC and route it to my speakers for monitoring via the mixer.
 
There are multiple ways to set this up, but one of them would surely work for you.  This unit has Main, Tape, and Control Room outputs, as well as an Alt bus, sends, returns, channel inserts, etc.  Very flexible!
 
Mackie 1202VLZ4 Mixer
https://www.sweetwater.com/store/detail/1202VLZ4

 Just get one of those Behringer mixers for about $50.

If the aim is to run the guitar signal through Amplitube then to a guitar amp it can be done. It's not entirely simple though.

The setup would look like this.

Guitar -> interface (might need a DI box with a 1MOhm+ instrument input if the interface doesn't have one. Guitars like to "see" a high impedance otherwise they lose a lot of treble and volume.

Interface sends signal to computer, and through DAW/Amplitube. You'll need to enable track echo if Amplitube's loaded into a DAW to hear what Amplitube is doing.

DAW sends signal back to interface. Not to the stereo outs connected to the monitor, but to another available output. The audio track's output will need to be configured to point directly at that output.

The interface output carrying the guitar should then be connected to what's known as a "reamp box". This is a special kind of DI box that converts a line-level signal to a guitar level one suitable for running into a guitar amp. Connect the reamp box output to the guitar amp.

Then record the output of the guitar amp using a microphone or maybe a speaker-emulating DI box of some kind. If it's a valve amp it absolutely must be connected to either a speaker or a load box of the correct impedance or you risk very expensive and quite possibly terminal damage to the amplifier very quickly indeed. The only exceptions are the Mesa Boogies and a few other amps which have a speaker emulated DI output and a built-in switching system to disconnect the speaker. Always follow the manufacturer's instructions when using such things.

Overall, it's a complicated way to go. Studios sometimes track a guitar twice at the same time, once track via the effects and amp, with another track recording the "dry" guitar in case they need to run it through different effects or amps later on. But it's a bit of wn overkill setup for most people.

I suggest a better way to do things is this.

Run the guitar directly into the amp. If there are effects that need to go before the amp - wahs, overdirves, fuzzes, compressors - consider buying a few inexpensive ones or good condition second hand. Record the amp, or use a loadbox and a speaker-emulating DI box like a Palmer or H&K Then add other effects - modulations, delay, reverb etc. - in the DAW.

What will not get good results, at least not without a great deal of careful setting adjustments, is connectong an output from the interface directly to the guitar amp. The output level from the interface will be vastly larger than the amp is designed to expect and it will probably distort like mad, or if the interface output is set low enough to avoid that you'll probably get a lot of hum. It's also quite possible there'll be a major ground/earthing loop set up as well which will buzz like mad.

:-)