Anxiety and clutter make for a bad combo

So for those who have known me a while, you all know that I have anxiety....but some may not realize to what extent. Anyhow, some things it is minor, others huge. Well lets just say that my house and life also has clutter and those 2 things together can be a horrible combination. So I have been trying to de clutter and make room in my house and my life. I rearranged Kaitlyn's room, I have been trying just to get rid of things that I know have not been used in months, but it is hard to look at the big picture when there are so many little steps. Everything you read says just do a little at a time and break it into 15 minute clumps...it doesn't all need to get done at once, but for me 15 minutes makes me feel like it will never ever be finished and then comes the anxiety followed by the depression. Take today for example. I spent an hour and a half cleaning out the garage...filling up a whole garbage can and recycle bin, and making 3 large bags for donation. I look at what I have done and I think WOW....you did a lot(well when looking at a little picture). Then I look at the big picture and think, what a waste, this is never going to be finished and then it gets frustrating and upsetting and I just want to give up.....I guess it doesn't help that neither my husband or I are neat freaks. I have told my husband that we need to hire a professional organizer because I think that a lot of this stuff for it to get accomplished is beyond the 2 of us. He being an engineer thinks it is a waste of money to do that...so here I am back at square 1. I should be thrilled that the garage is coming together and Kaitlyns room looks great, but instead I am unhappy about how much more we have to go......