Matt,
As I read your post, one can easily sense that here, indeed, is a very insecure person and he knows it. So what is the remedy?
If we work at the root of it, take care of it, the rest should fall in place. And that is not too hard.
The root as I perceive it is a too much emphasis on "I", self. You focus so much on "I" and you are losing a healthy perspective of reality. Think about that a moment!
How to remedy this fixation on self? It should go without saying but you need to get ALL of your sins under the blood, OK? Nothing else will work if this is not taken care of. Now that you are washed clean, you ask Jesus to show you what HE wants you to do. Be yoked together with him - understand this analogy? When one is yoked with another, one has to lead, just like a team of horses - there is a lead horse, if not. the team cannot pull. Now be very sensitive to the HOLY SPIRIT and do as he bids you, knowing He will not ask you without HIM giving you the power or grace to fulfill it. Do NOT look at yourself at all, do NOT even consider whether you will be able to carry it off. NO! NO! no looking at yourself! Period!
Ok, now look to Jesus. When you are in a situation and feel that fear coming on, just ask Jesus, "well, now what would you have me do?" and then do it when he tells you. Simply put, it means submission. That is all. Simple but so hard for those who are self-willed and I would guess all have to deal with this on some level. Think of others and how you can best help them! Do not think of your abilities or lack of them. Just do it. And you know what will happen? You will find that fear leave you. ("For God hath not given you a spirit of fear but of a sound mind.." 2 Timothy 1:7. There is another fear one should have but it is not the kind we are talking about here).
Mind if I share a testimony? You just read it! Actually, I used to be so afraid of people - my husband still talks about it when the subject comes up. Many acquaintances today will find this hard to believe. Today I fear very few people, thanks to the Holy Spirit. Knowing this comes from the LORD, I know that when my eyes are diverted to myself, fear sets in and woe is me! Remember the story of Peter walking on the water: when he looked at his progress, his surroundings, he started sinking. There is a profound principle involved here. Do not forget that!
Hope this helps!
ginnyrose