Middleageseeker,
Welcome and good for you for going vegetarian!
I too live with an omnivore, and I have been strict vegan for 5.5 years. At first he was really against what I was doing because he didn't really understand it, and he didn't want to give up his favorite foods. It's taken a lot of patience, sharing of what it means to me to be vegan, and setting boundaries and being firm. I made it clear from the start I would not be buying or preparing animal products, but would still make vegan dinners for him. If we eat out we each pay our own way if he has to have his dairy or meat, but over time he has stopped eating meat/dairy even eating out because he knows it upsets me. Being clear in what is acceptable to you and what isn't is very important. It's important that your partner understands your motivations, needs, and desires. Being clear and firm in my convictions has helped my partner respect me more. I even once threatened to leave him if he continued to make jokes about being vegan, and that promptly stopped.
Over time and making some awesome dishes, he warmed up to it all and now actually prefers some vegan products and dishes. He also now eats almost totally vegetarian at home, but won't give up his dairy/cheese. Though he also likes my vegan mac and "cheese". I have found that he LOVES my homemade nut based "cheese", nut based sour cream and cream cheese (mostly cashew or almond based). I make a mean waldorf salad with cashew mayo. My partner comes from a background of hunters and dairy farmers, so you can imagine how different this all is to him. He has changed a lot though, has become more sensitive to the plight of farm and certain wild animals (he joined me in protesting the Minnesota wolf hunt for example). He also loves UFC fighting stuff, so when he learned some of the fighters are long term vegans, he became more interested and accepting of it. He also warmed up to it over the years seeing how successful I have been and how much healthier I am than I was for years. In fact I am way stronger than I have ever been. I struggled with being underweight and anorexic for years, but have come a very long way in recovery as a vegan. At any rate, you should never be forced or pressured to cook animal products to make your significant other happy.
Sometimes, what I do in the situation of cooking for my partner, is to make base items he can add his stuff to. For example, I will make baked potatoes and broccoli, and I add nutritional yeast sauce to mine, and he adds his cheese or whatever to his. Or I make vegan tacos and he adds his own toppings. Or ditto with spaghetti.
As far as dairy, I avoided it for years before becoming vegan due to intolerance, with the exception of plain nonfat Greek yogurt that I would consume on occasion, or tiny bits of mozzarella or parm cheese. When I went vegan, like andy, I pretty much avoided even vegan "cheeses" for several years, with the exception of homemade nut based cheese and nutritional yeast sauce (I blend nutritional yeast, plant milk, steamed sweet potato, spices for a sauce). They just did not appeal to me. I did miss Greek yogurt at first, and then I discovered that blending a half block of tofu with stuff like banana or lemon juice and pinch of sweetener or even cocoa powder makes a very thick, creamy, not too sweet, high protein pudding that is a lot like Greek yogurt with as much calcium and protein. That satisfies my need for creamy thick sourish stuff. I have also experimented with making homemade versions of vegan yogurt, and oatgurt (soaked and fermented oat groats...makes a thick creamy yeasty sourish yogurt like concoction that contains natural probiotics). So much of the fun of being vegan for me has been experimenting with creative ways of cooking and preparing plant food. It has really opened up worlds for me as far as variety. I used to make the same handful of dishes as an omni, and I thought "healthy" was always the same old tired salmon, brown rice, and vegetable dish. Even breakfast is far more interesting. the more dishes and ways of cooking and preparing food you discover as a vegetarian, the less you will desire that dairy!
Also, beyond food, I save money by cycling to work when I can instead of driving. I buy most of my clothes from second hand stores. I don't wear makeup or use hair products other than very simple organic vegan shampoo, so I don't spend much of anything on toiletries beyond basics. For cleaning, I keep it simple there too. I use stuff like lemon juice, washing soda, vinegar. I do on rare occasion use bleach but a bottle lasts me over a year lol. I used to wash my hair with vinegar, tea tree oil, and water only, but after a few years got tired of that and started buying Dr. Bronners liquid castile soap. A small bottle of that lasts me several months, even using it for cleaning purposes beyond my hair and body (it is all purpose).
I've also photographed with my Iphone recipes from vegan/vegetarian cookbooks instead of buying them lol. The library was my best friend in the beginning. It is amazing how much material you can find at the library now on everything from vegan and vegetarian health, ethics, cookbooks etc.
Best wishes!