VVell, the social anxiety if anything could be sourced from the addiction in that of being found out. You may have an underlying fear of someone happening upon what you have been doing in private. Maybe you feel like a phony, or you're keeping this deep dark secret and its eating at you. You may not even notice it, until someone almost finds out but doesn't and then the emotions sink in. "VVhat if they found out? Oh no!" So in that respect, one might be anxious I suppose.
Truth be told, even if you blocked all those sites, and what not there is still the underlying issue of lust. Its not even the porn that is the issue, it is lust. You don't need those sites to relieve yourself, you'll find something else. You need to get to the root of the problem. I think a good portion of men, believers, have dealt with lust and in my own experience the Lord's answer was "Kill the eye of lust."
The question is, how do you kill the eye of lust? To me, this doesn't necessarily reference a solution of practicality like blocking sites, and what not (getting rid of magazines, tv channels, etc). To kill the eye of lust it seems is to kill it at its source, in that of a mindset or way of thinking. For what reason do we lust? Is there an emotional excuse? A fear? VVhat lie have you believed in that is not true compared to God's word and who He has called you to be?
Now we can ponder this from an internal perspective or an external one. External in that of the women. The eye of lust is looking at women without the mind of Christ. How does the Lord see these people? His creations? His children? People to one day become His adopted children? A person with a purpose, and one that the Lord loves dearly? Are such people, such women to be seen as viewing pleasure, or are they to be seen as sister's in Christ, or a soul to be saved? VVe are called to love, not lust. Right?
So all of this considered, you still may even in this moment be thinking of lusting once again. Remember that the Lord loves you and He doesn't condemn you. There is no condemnation in Christ, Jesus. You see the lie is that this sin, lust, has power over you. I am telling you that you are under grace, and sin shall not have dominion over you. You are a new creation in Jesus Christ, and you are dead to sin and alive unto God. You may claim this addiction, but know that you are His. He has claimed you, and He sanctifies us. Trust in the Lord, give this burden to Him. Ask that He give you the escape from such temptations, and to help you kill the eye of lust.
Porn is the scapegoat, go deeper and address the lust. You don't need internet to lust, you could be in a room alone, lights out, and still lust with the images in your mind. Seek the Lord's wisdom for to be set free in this area, ask Him for such wisdom. You are a child of God, and the Lord is for you, not against. Go to the throne of grace, seek Him. He is not only willing to set you free, but is anxious to. The Lord grieves for us, and not against us. He doesn't want us to experience the consequences of sin, but wants us to enjoy the fruits of righteousness.