[Q] New Rom 2.3.6 to 4.1.2 Samsung S Plus GT-I9001

Hello i hope someone can help me !?

I have an Samsung Galaxy S Plus GT-I9001 official with the latest Rom Gingerbread 2.3.6. so because i want to use some apps they start from Jellybean 4.0..... i have to change !

I have done already some work on HTC One m7 like rooting so i think that as i am an newby i know a little bit of how to do things, but now with my Samsung i am lost kompleet !

I fond here in the xda section an thread related to my samsung and changing it to Jellybean 4.1.2 what i did, and everything is working so far, have Wifi, make Phonecalls, send SMS and MMS enter into Internet and get mails. Now the Problem comes that i am not able to go into the Google Playstore !

I have downloaded the apk from phone installed it and when i open it (to download from my account apps) it closes emidetly ! I have tried to recover my gapps, deleted the cache of google play, forced to stop and started again but now way.

The other thing i expirence now is that i am not getting any connection over USB to my computer anymore, it is installing some drivers and i have now in the explorer one CD drive with letter (what seam to come from my phone) but when i start it it say to enter an cd/dvd.

What i have done wrong or is somthing missing !? I hope not that i have Bricked my phone. And when it will be not possible for me to install Jellybean then i have to see to downgrade back to 2.3.6. so how can i do this !?

Sorry for my English but my main language is German and i try hard !

Thanks for any suggestion

Addition to my Problem !

it seam that i have destroyed (Bricked) my Samsung, since my first thread i was trying on to solve the Problem but with no way i can get it o work with any gapps app. the other thing is that i wanted the finaly to try to get it downgraded with ODIN Multidownloader, but like i see now in the ROM what was given from the XDA Forum there seam to be no MTD driver so the ODIN Multidownloader nor the Kies would identify or see my phone any more!

I that case i have to live with this and only can use the phone for Calls,SMS, Mails and nothing else ! At least somthing so the phone is not totaly useless ! :laugh :laugh:

What it looks like is that nothing is on the Phone like Framework, Downloadmanager, and all related Googel apps to work fully or make connection to Google Playstore and Computer USB for Kies.