I have two ways of answering this, take either depending on your disposition.
The first answer:
Motivation does wax and wane fairly frequently when it comes to training, especially if you're not seeing the results you want, the trick is to make training a habit instead of something you have to really push yourself to do.
Training as a habit trumps motivation every time.
For the training itself, what are you training for? To paraphrase Viktor Frankl (though I believe it was originally said by Nietzsche):
With a why, man can endure any how.
Over the past several years I've watched a lot of my family and friends suffer health issues due to their being overweight and out of shape. My why is that I refuse to be like them, while they're sitting in an old persons home, I'm planning to still be hiking the hills and pulling deadlifts.
Find your why.
The other option is to find something you enjoy and do that. I'm a passionate rock climber, so I do that which helps keep me in shape (and due to my love of rock climbing, I train to become better at it). Swimming, walking, paddle boarding, running, gymnastics, powerlifting, strongman, there are so many options there will be something you enjoy. When you find it, find a community around it and make it part of your life.
For your actual training, if you didn't get on with the 5x5 program, then look pick another one and stick with that for 6 months or so. Jim Wendler's 5/3/1, Dan John's Easy Strength, DeFranco's Westside for Skinny Bastard, a basic PPL program, there are countless options out there.
If you're not progressing on a well established program, then the issue is very likely not the program itself, but your nutrition / sleep / stress management or implementation of the program.
If you've got the money, hire a personal trainer to give you someone to keep you accountable. If not, join an online community and start posting your training sessions online and find accountability like that.
The second answer:
Man the f**k up.
Lazy is a state of mind. If it's due to something like depression, then that's a completely different issue, if you're just not finishing your training sessions because you're getting bored, then stop acting like a delicate little snow flake and just do the damn work.
You think world champions have endless motivation and love every training session? Hell no. I've had the privilege of training alongside some, and I've seen them sitting before a session moaning and bitching about not wanting to do it, being tired, kids having kept them up all night, not feeling 100%, then they go and do it anyway. Why? Because they know it's what they need to do. They embrace the suck.
Assuming a session is about 60 minutes and you have a few sessions a week, that's 180 - 240 minutes out of 10080 minutes in a week. That's around 2% of your week. Are you seriously saying you can't knuckle down and do the damn work for that short period of time? If so, I got news for you, you're in for a rough ride the rest of your life.