How should I thank my in-laws for everything they done for me

My brother-in-law [31m] has been close to my family even before I was born. He went to elementary school with my oldest sister and his now wife [31f]. They started dating when they were about 14 if I'm remembering correctly. My late mom [52f] was pregnant with me at the time. However, their relationship was off and on when they were teens, and they really didn't get serious they were in college.

He and his sister [38f] were even the go to babysitters for me and my other two sisters [22f, twins] when we were very young. They were the fun babysitters, and they used to take everywhere we wanted to go, like bowling or the local mall. As such, he's been a part of my life for as long as I can remember. When my parents passed away, he and my sister took me in.

I've known my sister-in-law [27f] since I was 10. My brother [26m] met her at a bar when he was in the army and deployed to Germany. She was a Romanian-Ukrainian woman who traveled to Germany in search for a job. They hit it off right off the bat and hooked up pretty quickly. The first time that I saw her was when she flew to the states to visit my brother and met our family.

She made a pretty good impression on us, despite her accent being a little hard for me and my family to understand at first. My now sister-in-law took me, the twins, and our little nieces to a theme park during her stay. This was a very rare treat for us, as the park was a bit far away and expensive for our family. She and my brother got married a few months later.

The both of them have done so much for me over the years. They openly refer to me as a brother, despite us not blood related. My brother-in-law feels like something like a cool dad, uncle, and older brother all wrapped up in one. He was the one who taught me how to drive stick shift, how to fish and hunt, took me to a car dealership to search for my first car, and I went with him to my first concert. Although he could never take the place of my bio dad, my brother-in-law has tried his to best to fill in his shoes.

I used to have a small crush on my sister-in-law when I first met her, but she is pretty much my older sister now. She has taken me on several rides on her motorcycle, has tried teaching me how to speak Romanian and Ukrainian, goes shopping for me all the time, and loves giving me dating advice. The three of us often bond with video games, movies, and books. Whenever I'm sick or injured, they drop everything to help take care of me.

They are also both very protective of me. Last year, I was in a toxic relationship. Won't go into too many details, as that is a story all in itself. However, a short gist is that my ex was very controlling and possessive of me. She would bomb me with dozens of messages an hour, and get upset if I didn't respond right away.

Most of those messages was her interrogating me over what I thought of her, with some occasional suicide threats if I dared to leave. My ex also demanded that I stayed away from all females other then her, which included my own family. One time, she had a meltdown when she witnessed 31f kissing my forehead while taking me home from school. I tolerated all of that no matter how miserable it made me, as I thought I was in love with that girl.

Needless to say, no one of my family (including my in-laws) liked her at all. Both my sister-in-law and brother-in-law, along with my other siblings, tried encouraging me to dump her dozens of times. This all came to a boiling point one day when I chose to hang with my two in-laws over my ex at my sister and brother-in-law's house.

As I was playing some halo with them, I got a text from my ex demanding that I go outside. I looked out the window and there she was standing in the driveway. My in-laws tried telling me to stay put, but I went out to see what she wanted. My ex was furious that I blew her off and accused me of cheating. She then started hitting and kicking me really hard.

After what felt like an eternity, my ex suddenly stopped and started trembling. I looked behind me and there was my two in laws glaring her down. They berated her for hurting me like and told my ex that we were done. She tried apologizing, but they wouldn't have any of it.

My brother-in-law told my ex that he was taking her home and they were going have a word with her parents. As he drove away with her, my sister-in-law asked me for my phone. When I gave it to her, she looked through all of my texts with my ex. She screenshotted many of them, texted them to herself and other family members, and blocked my ex on my phone and every social media that I had. My sister-in-law then lectured me on learning how to be safe in relationships, and added that she lost one of her aunts in Romania to an abusive husband.

Our family gathered up in the evening to discuss my ex. My siblings and in-laws decided that we should report her to the school administration. The school separated us as much as they could, which included removing her from classes we had together. Several weeks later, my ex's family moved away and I never heard from her again.

Without my in-laws and other family members, I don't think I wouldn't be able to escape that relationship. They helped me in my lowest moments, and I just don't know how to thank them for thank. I love them both so much and I want to show my appreciation. I've tried doing many chores at their homes and babysit their children whenever I can.

However, I don't that is enough. What can I do to show my gratitude towards my in-laws? Any advice will be appreciated.

TL:DR: Both my brother-in-law and my sister-in-law have done so much for me over the years, I just want to find a way to pay them back.