One of the first things I tell parents who have a child who's been newly diagnosed with autism is to take their time. Dealing with autism is a marathon that never ends. If you don't pace yourself, then you'll burn yourself out and all the challenges will still be there, getting worse while you have no energy to cope.
It's a tricky balancing act for every family. Do I challenge the administration at my local school or shop around to try and find friendlier classrooms? Do I pay for an intensive therapy program or take time from my job to do the day to day work? Do I push for more socialization and playdates or do I focus on improving academics? Which lifeskills are most critical and which ones can be learned later? The list goes on and on and, as a parent, there's always the nagging guilt that you've chosen the wrong ones.
It feels wrong to take time for yourself when your child needs so much, when you know that withdrawing some effort can have a huge effect on their long term prospects. And yet, at the same time, if you drain yourself too much, you can find yourself with no choice in the matter. Eventually your body will insist on rest, even if it has to knock you into the hospital with a massive infection to get it.
So I tell parents to take their time and figure out what is sustainable for them in terms of time, money and effort. These are decisions they will have to live with for a very long time and being honest up front about what's possible will make life much easier in the long run. If your spouse is in denial, don't expect them to take an active role in therapy or research. If your extended family isn't good at dealing with the child, don't expect them to be able to give you respite. If having a trip to Florida every year is an important part of what keeps you sane, then make sure that trip stays in the budget.
It's not selfish to take care of yourself. As a parent, you are the only thing standing between your child and the world. They need you in top shape so that you can continue to be their advocate and protector.