Can loneliness cause depression?

I wonder if you have had personal experiences with that problem. I am married but my husband drives truck over the road, he's gone 3-4 weeks, spends 2-3 days home when he comes. Really when he's home, he spends most of his time in the computer. I do EVERYTHING when he's gone, I pay ALL the bills, I go grocery shopping, I keep our house very clean and organized, the yard mowed, put garbage out, wash the car every week, bathe our 2 dogs and take care of them, go to work everyday (I'm a CNA), fix things that break in my house, take care of the garden, grow vegetables and pick them, take care of myself physically (walk everyday, eat well, do my own nails, etc), read books, do my quilts, study (going to start my prereqs for nursing school soon), etc. I am not American, and I have no relatives in the country. We've been living in our place for 2 yrs now, I've tried making some good friends with some people from my church, but it seems that they have their own little groups. I try reaching out for them. On the weekend I get really really bad at being depressed and lonely, especially at night time. I leave the TV on for most afternoon on Saturdays and Sundays, at least I hear somebody talk. I hate total silence, unless I'm reading a book, but I still leave some kind of noise so I can think someone is around me. Some moments I like to stay by myself, I think it's healthy to stay alone sometimes. But staying alone all the time and being rejected all the time by people kinda puts me down even worse. As I said, I am a CNA, and I take care of 2 Alzheimer's patients in a home health setting right now, and it really makes me feel good to be helping them, as they appreciate my help and I learn a lot with them (patience, endurance, compion, etc). But I would like to feel good in my personal life too! Don't I have this right? What should I do to improve my loneliness/depression? I appreciate your honest and serious opinions. Thanks a lot.