Thank you for bringing your question to Just Answer!
I hope that you will put off any decisions to make this a permanent relationship until you have seen consistent, long-lasting changes in his behavior. I see some red flags in what you describe
1. no friends--possibly means other people see there is a problem in how he behaves and interacts with others.
2. excessive neediness
3. poor judgment:--not a quality you would want in a husband.
4. multiple promises to change with no results that last.
5. doesn't think--again, not a quality that shows husband or long-term relationship potential.
6. whiny and clingy: This can be a disguised method of control--by being so needy, you end up having to cater to his insecurity and whining.
I know you feel a certain attachment, especially since he is your first intimate partner, but he has many of the characteristics of a controller in the making. You might want to find a therapist to help you evaluate this relationship in more detail and to help you decide if this is a healthy relationship for you to be in. Staying with someone because you feel sorry that they don't have anyone else isn't a good enough reason to stay.
You are new to relationships, so please don't assume that this is the only trustworthy person you will ever meet. You will find someone to trust, who also is mature enough to live his own life without clinging.
Think about what you would say to a girlfriend who you really cared about it she wrote you an email like the one you sent here...it would probably be very similar to my advice to you.