You should try first what Raven Queen suggested you to do (e.g. Kegel exercises).
Kegel exercises (including Leg up exercises):
What these exercises do is strengthen the pelvic floor muscles, which can help tighten the vagina. The great news is that these exercises are easy to perform, you can do them anywhere, and they don’t require any special equipment.
Here’s how it works:
First, you have to find the right muscles. To do this, try stopping urination midstream. These are the exact muscles that you need to work. Once you get a feel for how to activate these muscles, you can do these exercises in any position.
Start by tightening your muscles, and holding the contraction for five seconds.
Now, relax these muscles for five seconds. Do this four to five times in a row.
Eventually, you want to work your way up to relaxing and contracting for 10 seconds each. Repeat this three times per day, and remember to breathe freely during each session (don’t hold your breath).
Gels:
According to many doctors and surgeons gels based on ingredients like Aloe vera or Manjakani Extract (this potent herb is rich in vitamins C and A, carbohydrates, proteins and minerals) are a waste of time and money. They won't get you the same results of women who undergo surgery.
Vaginoplasty/Hymenoplasty/...:
It is permissible to undergo such a procedure with the intention to please the husband only if you have tried everything the natural ways first to avoid this.
Sources:
http://www.islamweb.net/emainpage/index.php?page=showfatwa&Option=FatwaId&Id=127053
http://www.vaginaltighteningwand.com/how-to-tighten-your-vagina-naturally/
https://www.realself.com/question/california-md-virgin
https://islamqa.info/en/1006
