I'm not sure if this question really falls into the DIY category, but it is interesting and I'm sure shared by many inspiring DIYers.
You have already committed to the project so some of this advice is not timely. I think the most important factor in DIY work is understanding the scope of the project, and the skills needed to complete them. Working on old homes, doing renovations is always littered with land mines. Expect the unexpected, be prepared to spend at least twice the time you estimated, and usually 20 to 30% more money. Do not fall prey to the over simplified DIY shows on TV where a 40 hour job is miraculously finished to perfection in 30 minutes.
It is wise and often cheaper in the long run to get professional advice or help with parts of your project that require specialized knowledge and tools. Plan on doing what you can do comfortably and avoid the stress of "what do I do now!" Many of these situations can be eliminated by proper planning and realistic expectations. Too many DIYers bite off way more than they can chew, resulting in frayed nerves, unfinished projects and substandard construction.
In your case, you need to take a break, reevaluate the amount of work to be done. Honestly decide if your skills and time are enough to finish the project without ruining your family and professional life. Perhaps you could plan to work just one or two evenings and all day on one day of the weekend. Since it always seems to take a lot of time to get started, get tools and materials ready, trying to do this in 2 to 4 hour segments is not productive and very frustrating. You need to make a plan, divide the work into bite size chunks and completely finish one before moving to another. Maybe it would be worth hiring a pro or good handyman to help you get through the rough spots. not only would the project move faster, but you will get an education and use of tools and techniques, and most importantly, peace of mind seeing things happen. Take that break, take a deep breath, relax a bit and set new goals and time lines.
Best of luck to you. you can come here with any questions about your project. There are a lot of very smart and experienced folks here more that willing to give you detailed and accurate answers to your questions.