I'm so sad. I'm crying right now

. He didn't hurt her or anything, but this problem is what I just can't stand.
We were coming out of my aunt's house and a lady was walking a yorkie girl. Bengi usually barks at any dog at a distance, but he's actually scared of bigger dogs, not dogs his size. Well, he was pulling to get closer to the yorkie and the lady was like, can she say hi? and I say yes and put him down, and he started to get slowly closer to her, like to say Hi, but they went right at her, attacking. It look like he was trying to bite, but he didn't.
I know some time ago I said I was going to talk to a trainer, but I didn't because I thought he was getting better. Now this tells me I have to really address this and also control him better and not let him get close to other dogs until I know he's cured. Sometimes he's ok with some dogs, but you never know which one he's fine with and which ones are not, and I cannot take chances... I was so embarrased!!!!

The lady was like, oh are you ok baby??? (checking on her yorkie). I know how she must have felt... I would be the same way if other dog would attack Bengi.
I know he's not trying to hurt anybody, but just telling them to stay away...
I need to work on this with him. I'm searching for dog trainers in the area. Please pray for me and Bengi because this takes discipline, specially from my part, and we all know that this is not fun like teaching them cute tricks... this is 10 times harder... please pray for us and if you have any experience on this, please share. Thank you so much