If you do them regularly, a few times a day, that will strengthen the vaginal muscles. The vagina is very flexible. Most men probably can't tell the difference from one vagina to the next just from their penis. Another thing that affects this is the level of sexual arousal. Some women who have had difficult births or a lot of children might have a surgical procedure done to tighten their vaginas.
Opposites attract and similars attract.
Love is composed of all sorts of different things. It takes all kinds. Yeah, if you are crying after masturbating, it sounds like you are very lonely. I would make finding someone a very high priority. Maybe you have a hint of shame from having to masturbate because you don't have a partner.