Help plz

I didnt know where to post this hopefully this is okay here..

Just need to rant about this because I dont know what else to do and I feel this like is really affecting my mental health.

We have a 6 year old beagle cross who weve had since he was a puppy who we love more than anything but he has alot of behavioural issues, he has severe separation anxiety which means he can't be left alone this has been going on since he was about 2 I feel like we've tried everything , training, doggy day care (too expensive) He used to be crate trained whilst we worked but then he started becoming aggressive and going for us when we tried putting him in, then we started leaving him in a safe part of the house only to come home to it being destroyed lino ripped up carpets ripped apart so we no longer leave him i take him everywhere with me and have to leave him in the car when im doing something where he cant come. I now have a toddler who is 3 and I walk them both but its getting ridiculous he will pull constantly, he is very strong and has nearly pulled the pram over on several occasions. We also live in a flat so getting out the house in itself is hard work. If we have anyone round he will plays up & steal items and if you try and retrieve them he will get aggressive. We've tried rescues no one will have him because of his aggressive he shows sometimes he doesn't show this alot tbh. We've tried pets4homes and we have had interest but not the right sort of person we feel would be the right fit. I feel constantly stressed out with him and like Im trapped living my life around him. Isit just me or could other people cope with this? People have said to get him put down but we are completely against that as his only 6 and the aggression he shows is only really when his guarding something. I really dont know what to do anymore, its not fair on him or us.

Thankyou for reading

❤️