I recommend you read Feel the Fear And Do It Anyway. It is an old school self-help book but an absolute classic. It will help you not care if you go to an exercise class that is wrong for you, or you try to befriend someone and it fizzles out.
The best thing in it is the 9 squares life plan. Draw a big square, divide it into 9 sections and put a key aspect of life in each square. E.g. Home; Family; Work; Fitness & Health, Friends, Hobbies etc. One square has to be Community and iirc having Spirituality in one is recommended.
Then you just do something tiny each day, small each week, medium each month and big each season to improve each area of your life giving equal importance to them all.
So tiny for Home could be buy some flowers or throw out something broken that you'll never mend. Tiny for family could be give your DC a hug, for friends it could be posting something on an old friend's FB page. Tiny fitness could be just taking time to stretch in the morning. Tiny spirituality could bedoing a 5 minuteYouTube meditation, or if you are religious, saying a prayer.
Small could be doing a 15 minute online workout, cooking a favourite dinner or brunch to have with your DTeens, having a coffee with a friend or neighbour who is warm and upbeat, spiritual could be taking a walk in nature and really focusing on the turning seasons.
Medium might be trialling a fitness class or choir, booking a half day weekend workshop in painting, taking Dteens to a show or for a day out, repainting and rearranging furniture in your bedroom. It might be deciding to have one quick 30 minute coffee date with an OLD every week for six weeks. Or booking one of those free John Lewis stylists to help you try out new looks.
Big might be going on a meditation retreat or booking an adventure holiday alone or with DC, training for a long run or bike ride or triathlon, writing a book - something doable but a challenge. If one of the big things is a real challenge, make the other big things manageable. Don't set yourself up for stress or failure or burnout. Focus on milestones eg Helping a teen decide on unis to apply for and settling them in to uni, or supporting them through GCSEs with healthy food and testing them on revision is a Big Thing. Don't also run a marathon and move house that same year unless you are feeling superhuman.
Within a year you will have a full, happy, well-balanced life. You will feel confident and engaged with the world and you'll know yourself better.You will be aware of making time for the big milestones and stressors and not overloading yourself elsewhere. You will automatically prioritise your fitness and health. It is the absolute recipe for happiness after heartbreak or life-shattering disappointment or just that slow boiled-frog state of life getting into a sad, small rut. It works like a charm.