I am 30 year old man, got married 2 weeks before, facing trouble inserting penis in wife's vagina since it's her first time too. I am not able to keep my penis hard for long time. We started fingering her vagina to increase size. When I try to insert my penis, it bends, may be because of not having enough hardness or small vagina size.
I was married at about that age and had a very similar problem. After 6 months it has improved slightly. I suspect it is either Vaginismus or a tense hymenal ring. We have been inserting things of progressively larger size trying to widen the opening. The other thing that helps is intense arousal. If the timing and circumstances are right, the opening will be large enough to accept a penis. Keep in mind that there is likely a phycological component to this as well. I would suggest being patient and slow. I read somewhere that it can take years to solve this type of problem.
If your penis is bending while trying to insert, it means the problem is your penis is not erect enough, it has nothing to do with the size of her vagina. Your erction problem may have to do with a poor diet, or maybe your not getting enough sleep, or high stress.