I also did the same stupid mistake that you did. I accidentally ran baseband dowgrader on my 1.1.2 OOTB phone. I lost my wifi etc. Don't worry, proceed with the h/w unlock process. you will be able to get everything back. I got my wifi etc back. Now I am on 3.9 bootloader & 1.1.2. Everything is working fine.
As you lost wifi, you should use ibrickr to downgrade to 1.0.2 and to put the required applications on your phone. Search the forum on how to use ibrickr. Then use the ienew, uenew, secpack, nor provided by geohot. Its a tedious process but you will reap the benefit. All the best.