Do you do anything just for you, OP? Even if it's the odd walk or swim, going out for coffee etc? I think having a break from a baby can make a big difference!
There's kind of an end of honeymoon bit with a baby where you go, ok I'm getting through newborn stage, I'm getting through weaning stage - oh no does this shit actually go on forever? But remember each bit ends, and a new bit begins that will be hard in some ways and delightful in others.
Good things about bigger babies/toddlers
Genuine interaction and they begin to have their own ideas about things
Watching a child learn language is a delight
You can get childcare and babysitting for them more easily
They are less whingy (usually) as they're more mobile
Better sleep
Less fragile and more robust with illness etc
More things you can take them to
More independence - can sit back at playgroups and playgrounds and keep an eye instead of having to be with them the whole time
Bad things about bigger babies/toddlers
Tantrums
Breaking stuff and putting things in their mouths
Not letting you rest much when they're learning to walk
Sudden weird food preferences
I found it helped to read some books about child development and understand why they act like they do. It's also good to go out and look at other kids and think that will be yours in a blink of an eye - what will your child be like at 1, 2, 3, 10?
I have a 6yo and a 3.5yo, they bring their own challenges (6yo just decided she wasn't going to ever wear school uniform again and needed a lot of coaxing to get out of the house, eg) but equally they play a lot more independently now and I can go out more, sit and read etc. I'm sure when they're teens then today's problems will seem quaint and easily solved compared to cyberbullying etc. You just have to take it as it comes.
Are you getting help for depression? Are you getting good food, just about enough sleep, some exercise and time in green places etc?