hi Danutfrompitesti
I'm afraid it may be needle in a haystack time. You can try a couple of things but you may be out of luck.
You said you have a new phone. You could try to restore that phone from a backup of your old one and see if the videos are there
Restore your device from an iCloud or iTunes backup - Apple Support.
You could also do a blind search on your C drive and see if there are any files. I believe phones shoot video in the .mov format. So in windows explorer, click on your C drive and in the upper right corner of the window (this does vary from windows version to windows version so just look for the search box) type in .mov and let it search
it will find every mov file you have, but one of them may be your lost movies. I believe videos shot on phones or iPods just have a generic name, such as MOV_4837.mov so you may need to look at and check every one.
A good program to play mov files on a windows computer is mpegstreamclip. It's a free download (just google the name) and does a much better job than windows media player.
Happy hunting and good luck.