89 Barefoot Oil Leak (454)

Oil I drained out was plain oil. Was black though because I used it a lot last year

Yea I changed the oil since then dip stick oil does not look thick like it does in the bilge 

Need help, boats been leaking a good amount of oil. I have used the boat for about only 8 hours this year and have already needed to add a quart of oil. Bit of a backstory to my problem - I had a new mooring cover made for the boat and the guy ended up having the boat all winter. Boat was winterized properly except for me taking the drain plug out, because it was stuck (I am really dumb for not tending to this before I sent it away). I was supposed to get it back for thanksgiving last year then I was going to tend to it, but that never happened. He told me he was going to keep it inside a heated garage all winter, but took it out in the spring to work on my cover. I get my boat back in the middle of May to find my engine compartment filled to the brim with water. However I don't think the water froze because there is no cracks on anything in the bilge, and it hasn't sunk yet lol. I had to replace the starter, which was full of water, and ignition coil, moisture got to it. Now to the leak - I have found only 1 leak, at my oil filter which I believe is coming from the brass nut on top of it. Not sure what its purpose is. My bilge has this light brown oil water in it - a good amount of it as well. Oil pressure seems to be fine (about 40 psi at idle and like 70 - 80 psi underway). I am 18 and have practically no experience with engines and have only had the boat 2 summers now (0 issues with it last year) after it was handed down to me after my dad passed, who owned and maintained it himself for 20 plus years. Not sure if its hurting it because the boats running great but if it is I want to stop and fix it if I can.