"He told me when we first started dating that he has a tendency to push people away when he is stressed."...............Heed to what he has told you and give him some space.
I think it's wise of You to not want to be "needy or clingy", so I think You should not BE needy or clingy. You don't need to "pull away", just be there and be available to talk if He wants to. And yes, give Him "some space" and don't "text Him constantly", otherwise You will appear "needy or clingy".
It may be something quite simple, as in stress from work and He may not feel the "need" to "talk about it". Guys don't do the "needy, clingy" thing, they don't "need" to talk everything to death - that's a girl thing. It's not really likely that He will "confide in someone else" or "never discuss His feelings" - it's highly possible this has nothing to do with "feelings". That too ("feelings") is a girl thing. Guys are more cut and dried about situations.
P.S.
My husband and I were best friends for 7 years also when We came to realize We wanted to take our relationship to the N E X T level, that what We had for one another was much deeper and more profound than love for a friend. We just celebrated Our 29th(!!) Wedding Anniversay and We are just as happy and as excited in our love and relationship today as We were on that day of "revelation"!!
We like to say: True Love Is A FriendShip Set On Fire
Good Luck To You.
Hi, he is he and you are you and im sure there are things that you consider part of your personality. Hes told you that he is this way and part of lasting relationships is respecting and accepting these things.
If you try to force this issue he might construde this as being naggy and clingy.