I'm a sinner. First let me get that out there.
The critical issue is not whether you are a sinner (since all have sinned). Are you a sinner saved by grace, and is your wife a sinner saved by grace? This is where you both have to start.
I react out of anger sometimes and I'm critical. That said, I'm working on those things.
Even the saints get angry and are critical and need to work on those things.
Last week my wife said she does not love me like a wife should. She says there is a lid on that jar and it's empty.
So now comes the hard part. Have you asked her if she is getting involved with someone else, possibly another firefighter?
That said she does kiss me, want to hold my hand, cuddles me and we have been intimate since then.
This could indicate an attempt to hide the true situation, or it could mean that she is trying to deal with some issues and coming out with "I don't love you" instead of focusing on the actual problems. You will have to have a serious sit-down with her and try to get everything out in the open (including anything on your side.
I'm afraid of loosing my marriage. We went to counseling together and I am working on me , very hard.
Obviously you want your marriage to remain permanent, but does she? and what did the counselor discover, and what did he recommend?
I'm afraid of being too needy with the unsureness has come insecurities I have never felt.
Neither spouse should remain in a marriage because either one is "needy". Genuine love for each other should cover everything. If what she has said makes you feel insecure, then all the more reason to get to the bottom of this. Either she is committed to a lifelong marriage, or she is not. I trust she will be honest enough to tell you the truth.
She wants me to be transparent and I am.
Depends on what she means by "transparent". She should have learned by now that men and women are constituted differently. Most men will not disclose or discuss their emotions, while women are generally the opposite. On the other hand if there is something which you are involved with that needs some further disclosure but cannot be fully disclosed (for whatever reason) then you should tell her frankly that there is only so much you can share, but there is nothing illegal or immoral in whatever you may be engaged in.
I'm worried that is hurting.
Not sure what this means, but if there are past issues that need to be resolved, then they should all be resolved at the same time.
How do I give her space to heal while showing I am changing and prove I am worth of her forgiveness.
Why does she need "space to heal" unless you (or someone else) has done some damage? If no damage has been done, then there is no need to conjure up imaginary hurts. As to being worthy of her forgiveness, it sounds like you have indeed done something serious enough which has led to resentment or anger on her part.
Bottom line: It is time for a frank and open discussion between the two of you, assuming that both can be honest and care about the ultimate outcome. However, if she is plotting a termination of the marriage, that will be a totally different outcome.
First of all, it's so hard to live with a critical person, so GOOD FOR YOU for working on this!! That's awesome! 
